What to look for

I bought Avnet's $49 Spartan 3A development board but it was discontinued not long afterward - right about the time when I decided I needed a few dozen more. I've since done some extensive research (thanks, Google!) to find a comparable thrifty thrill.

When choosing a development board, consider what you get with it and what you want to use it for. FPGAs are ideal for use with high speed peripherals, and in general it is much easier to buy a board that contains the part you want, rather than trying to add one on later (and inevitably giving up and upgrading to a more capable board). Examples of things you might want, and are quite difficult to add yourself:

Gigabit Ethernet

HDMI/DVI

PCI/PCI Express

External non-serial memory (DDR/Flash etc.)

Things that are relatively easy to add, and are not so much of a big deal to wire up yourself.

MMC/SD cards

Character (e.g. 16x2) LCDs

Anything I2C/SPI and relatively low speed

VGA (with low colour depth)

I like having a board with many (at least 8) SPST switches and LEDs, and momentary buttons. Unlike a microcontroller where it's relatively easy to spit debug information out of a serial port or to an LCD with a single C function call, debugging FPGA designs is a bit harder. LEDs provide a zero fuss way to break out internal signals for visualisation - if you're tracking the progress of a complex state machine, you can light up an LED when it gets to a certain point without adding any extra logic. While these are easy enough to add yourself, I find that it's better to get a board that has them so that you don't waste valuable user IOs or waste time investigating failures caused by your terrible soldering skills.

Some manufacturers promote a standard form factor for add-ons, notably Digilent with their very wide range of Pmods, the Papilio One's Wings, and Arduino shields.

If you would like to connect high speed devices (above 10-20 MHz) to your FPGA, make sure your board has an interface connector that supports the speeds you'll be using. Look for ground wires interspersed regularly between signal wires, high speed connectors (not just 0.1" headers), PCB trace length equalisation, and impedance control. Few of the cheap boards bother with any of these.

FPGAs can be a bit daunting, so check that the manufacturer provides:

Schematic diagram

A reference manual, describing all of the on-board peripherals

A guide to getting started, if you've never used an FPGA before

A reference design that exercises all on-board peripherals.

Reference designs can either be HDL or microcontroller-based, but in recent boards, most manufacturers seem to be moving to the latter. Bear this in mind if you don't have a license for the microcontroller and environment (e.g. Xilinx EDK/SDK is not free), as the code will be difficult to port to HDL.

If you're a beginner, you may benefit from buying a board that has a companion textbook which has been written specifically for the board in mind, and describes each of the peripherals and how to interface with them. Popular boards with larger user communities may also be worth considering above cheaper options. The most popular Xilinx boards are those made by Xilinx (none of them cheap enough to be listed here), Digilent and Avnet. Terasic seem to make the most popular Altera boards.

Open source toolchains

A long-standing complaint with vendor FPGA design tools is that they are generally enormous, complicated, slow, buggy, closed source, and are either expensive or have annoying license requirements. The open source community has made great progress in recent years to reimplement parts or all of the FPGA design toolchain and to address all of these concerns.

FPGA devices which are currently either partially or fully supported by open source tools include:

Xilinx Spartan 6

Xilinx Series 7 (Artix 7, Kintex 7, Virtex 7, Zynq with Series 7 Fabric)

Xilinx Ultrascale(+)

Lattice iCE40

Lattice ECP5

QuickLogic EOS S3 and PolarPro3

Some tools to check out include:

LiteX - A Python-based SoC builder LiteX Hub - collaborative FPGA projects based on LiteX LiteX-BuildEnv - An environment for building LiteX-based FPGA designs

Yosys - Verilog synthesis tool

nextpnr - a vendor neutral, timing driven place and route tool

SymbiFlow - an umbrella project for FPGA architecture definitions

Icestudio - an visual editor/IDE for Lattice FPGAs

Tim 'mithro' Ansell has an open offer to send FPGA hardware to anyone who has time to to contribute to open source FPGA projects but doesn't have any hardware.

Boards by FPGA manufacturer

Xilinx

Zynq

Xilinx's Zynq parts are supported by their Vivado high level synthesis design suite and include a dual-core ARM Cortex-A9, USB 2.0, and Gigabit Ethernet.

Name Price Device Notes Zynq 7000 ZYNQ7010 development board $42 Zynq 7010 A no-name board, apparently pulled from some equipment, which provides 256MB DDR, 128M NAND flash, SD card, optocoupled inputs, 1 button, 2 LEDs, and 42 I/Os. Some more information is available in this EEVBlog thread. QMTECH Zynq7000 Starter Kit $56 Zynq 7010 512MB DDR3, micro SD slot, 100 Mbit Ethernet, two LEDs, 62 length-matched and paired FPGA I/Os and 15 processor I/Os. Some documentation is available at QMTech's site and there are some observations in this EEVBlog thread, where there are some complaints about a lack of decoupling. DIPFORTy1 "Soft Propeller" EUR 59 Zynq 7010 A DIP-40 sized board that is designed to be pin-compatible with the Parallax Propeller chip. It has 16MB of flash, 46 I/Os, one RGB LED, one user LED, micro SD socket, and a proximity/light sensor. Sipeed Tang Hex $70-90 Zynq 7020 1 GB LPDDR3, 2Gb Flash NAND, 100Mbit Ethernet, four USB 2.0 ports, a TF slot, and 15 GPIOs. MiniZed $89 Zynq 7Z007S Includes a single ARM A9, 512MB DDR3L, 128Mb flash and 8GB eMMC, USB host, USB-JTAG, and USB-UART, 802.11b/g/n Wi-Fi, Bluetooth 4.1, and BLE, Arduino shield connector and two PMODs (38 total I/Os), accelerometer, temperature, and MEMS microphone sensors, one button, one switch, and two bi-color LEDs MYIR Z-turn Board $99/$119 Zynq 7010/ 7020 1GB DDR, 16MB flash, TF socket, gigabit Ethernet, CAN, USB2.0 OTG, USB-UART, HDMI output, 90 or 106 user I/Os (with 39 LVDS pairs), accelerometer and temperature sensor, JTGA, two buttons, 4 switches, four LEDs, and a buzzer. An "IO Cape" breakout board ($35) provides three Pmod connectors, camera and LCD connectors, and 0.1" header I/O pins. snickerdoodle $115/$245 Zynq 7010/7020 A Zynq board with 155-180 I/Os, 512MB-1GB DDR, 16MB flash, micro SD, 802.11n WiFi, and Bluetooth 4.0. A range of base-boards and add-on boards are also available, providing gigabit Ethernet, HDMI in/out, USB, JTAG, 0.1" I/Os, and more. PYNQ Z2 $119 Zynq 7020 512MB DDR3, 128 Mb flash, microSD, gigabit Ethernet, HDMI source and sink, USB for JTAG, UART and OTG host, I2S audio I/O, 4 SPST buttons, 2 SPDT switches, 4 LEDs and 2 RGB LEDs, two PMODs, and Arduino and Raspberry Pi connectors (around 60 I/Os, plus 6 analog inputs) Parallella-16 Micro-Server $126 Zynq 7010 Includes a dual ARM A9. Also available on the board are the Epiphany 16-core CPU Accelerator, 1GB RAM, 126 Mb flash, micro SD, and gigabit Ethernet. Parallella-16 Desktop $158 Zynq 7010 Expands on the Micro-Server and adds high speed expansion ports with 24 GPIOs (and other Epiphany signals), HDMI, and USB 2.0 host. Digilent ZYBO Z7 $199/299 Zynq 7010/7020 1GB DDR3 RAM, HDMI source/sink with CEC, VGA, gigabit Ethernet, USB JTAG, UART and 2.0 host/OTG, MIPI CSI-2, audio I/O, 6 buttons, 4 switches, 6 or 7 LEDs, and 40 I/Os (5 PMODs), including analogue inputs, and microSD MicroZed $199 Zynq 7010 1GB, 128 Mb flash, SD card, gigabit Ethernet, USB 2.0, 100 I/Os (48 LVDS pairs) and 2 PMODs, 1 LED and 1 switch EDGE ZYNQ $214 Zynq 7010 512MB, 128 Mb flash, micro SD, gigabit Ethernet, 802.11/b/g/n WiFi and Bluetooth 4.2/LE, USB for JTAG, UART, and OTG, HDMI Tx/Rx, VGA, stereo audio output, light and temperature sensors, 4*7 Seg LEDs, 5 LEDs, 4 slide switches, 31 PL I/Os and 4 PS I/Os. A 2x16 LCD module is included, and camera and TFT LCD modules are available.

Artix-7

Artix parts are becoming increasingly common in inexpensive development boards, taking the position previously occupied by the Spartan-6 in Xilinx's lineup, though they are only supplied in BGA packages.

Name Price Device Notes QMTECH Artix 7 DDR3 Core Board $50/80 Artix 35T/100T 256MB DDR3, 16MB SPI flash, 2 switches, 3 LEDs, JTAG header, and 108 length-matched I/Os. It's also compatible with a daughterboard which provides PMODs, USB-UART, camera interface, VGA, gigabit Ethernet, and more. There are reports that decoupling is insufficient, so beware. Digilent Cmod A7 $75/89 Artix 15T/45T A breadboardable module with 512KB SRAM, 4MB SPI flash, USB-JTAG and USB-Serial, 3 LEDs, 2 buttons, 52 digital I/Os, and 2 analog inputs. Perf-V $79 Artix 35T 4 switches, 5 buttons, 7 LEDs, JTAG 256MB DDR3, 16MB flash, Arduino shield connector, one PMOD, and some sort of high speed connector which supports expansion boards with HDMI and VGA. Larger FPGA sizes will apparently be available too. LiteFury $99 Artix 100T A PCIe x4 gen 2 development board with an NVMe (2280 Key M) connector. It has 256MB DDR3, 128 Mb flash, 4 LEDs, and 12 I/Os (including four LVDS pairs). Alchitry Au $99.99 Artix 35T 256MB DDR3, 102 digital I/Os, 9 differential analog inputs (8 shared with digital I/O), 8 LEDs, 1 button, USB-UART, and USB-C for power and programming. It has high density I/O connectors, but companion prototype/breaking ($10) and I/O with switches, LEDs, 7-Segs ($25) boards. QMTECH Artix-7 Wukong Board $100 Artix 100T 16MB flash, 256MB DDR3, 3 switches, 4 LEDs, gigabit Ethernet, HDMI output, USB-UART, GTP transceiver interface, 2 PMODs, and 40 I/IOs. There are reports that decoupling is insufficient, so beware. Arty A7 $129/249 Artix 35T/100T An inexpensive way to get into the Artix parts. It provides 256 MB DDR, 16MB flash, 10/100 Ethernet, USB-UART/JTAG, four PMODs, an Arduino shield connector (a total of 62 I/Os?), 4 switches, 4 buttons, 8 LEDs (4 of them RGB), and a one year licence for Vivado Design Edition. Numato Mimas A7 $149 Artix 50T 128 Mb flash, 2Gb DDR, USB and JTAG programming interfaces, gigabit Ethernet, HDMI input and output, GTP interface, micro SD, 3x7 segement segment displays, 6 buttons, 8 DIP switches, and 80 I/Os (40 length-matched differential pairs). Digilent Basys 3 $149 Artix 35T USB-UART, 12-bit VGA output, USB HID host, 16 switches, 16 LEDs, 5 buttons, a 4-digit 7-segment display, 4 PMODs with XADC inputs on one of them. A device-locked Vivado Design Edition is available for $10. Nexys-4 DDR $320, $159 academic Artix 100T Pushing the limits of 'cheap' unless you qualify for academic pricing, but attractive if you need the larger FPGA. Includes 5 PMOD connectors (40 low speed I/Os), 128MB DDR RAM, 16MB flash, 10/100 Ethernet, USB HID host, SD card, VGA, accelerometer, microphone, audio out, 16 switches, 16 LEDs, 8 7-segment displays, 5 buttons. The Artix's internal ADC is available on one of the ports. EDGE Artix 7 FPGA Development board $165 Artix 35T A full-featured development board with 512MB SRAM, SPI flash, USB-JTAG and USB-UART, 802.11 b/g/n via an ESP-12F module, BLE, 12-bit VGA, HDMI out, 4 ADC channels, temperature and light sensors, 12-bit DAC, 2x16 LCD, 4x7 segment display, Micro SD, 16 SPDT switches, 5 buttons, 16 LEDs, a buzzer, and 31 I/Os. Compatible SPI TFT display and CMOS camera modules are also available. ZTEX USB-FPGA Module 2.1a 129 EUR Artix 35T USB 2.0 interface via a Cypress FX2LP, 100 I/Os, 256 MB DDR3 SDRAM (16-bit), and 128 Mb flash. An inexpensive prototyping board (17 EUR) gives you 30 LEDs, 4 switches, and a soldering area. PicoEVB $199 Artix 50T 4 analog/digital/LVDS I/Os, one high speed MGT and clock reference input with U.FL connectors, MGT loopback, 3 LEDs, 1x PCIe lane, and onboard JTAG programmer in a NGFF/M.2 form factor which can be installed inside a laptop computer for PCIe development Numato Neso $300 Artix 100T 256MB DDR3, 128 Mb SPI flash, USB 2.0 interface for flash programming and 8 digital I/Os, JTAG, and 140 FPGA I/Os.

Spartan-7

Name Price Device Notes QMTECH Spartan-7 Core Board $30 XC7S15 16MB flash, 3 switches, 4 LEDs, JTAG connector, and 88 length-matched I/Os on 2.54" headers. There are reports that decoupling is insufficient, so beware. Spartan Edge Accelerator $36 XC7S15 An Arduino form-factor board with six-axis accelerometer, mini HDMI output, CSI camera interface, micro-SD, five buttons, two LEDs, five DIP switches, USB, and an ESP32 for WiFi and Bluetooth. Cmod S7 $69 XC7S25 A breadboardable module with 4 MB flash, 2 buttons, 5 LEDs (one RGB), 40 digital I/Os (32 on DIP connected and 8 on one PMOD), USB-UART and USB-JTAG Arty S7 $99/$119 XC7S25/50 256 MB DDR, 16MB flash, USB-UART/JTAG, four PMODs, an Arduino shield connector (a total of 62 I/Os?), 4 switches, 4 buttons, 6 LEDs (2 of them RGB).

Spartan-6

Spartan-3

Name Price Device Notes Pano Logic Zero Client G1 $20 (approx) 1600E A thin-client computing appliance that has been reverse engineered. Available from eBay. It features 10/100 Ethernet, VGA, USB2.0 host, audio DAC, button, RGB LED, 32 MB LPDDR, and JTAG. Waveshare $22-30 250E/500E Two modules that include a large number of digital I/Os (80 - 116), config memory, and four LEDs. An external JTAG programmer is required. miniSpartan3 $25/35 50A/200A A module with an HDMI port, 41 digital I/Os, a 4-channel, 8-bit 200 KSPS ADC, SPI flash, 32 MHz oscillator, three LEDs, two DIP switches, USB-serial and on-board USB JTAG. Elbert V2 $30 50A A board with a 16Mbit of SPI flash, 8 LEDs, 6 SPST switches, 8 DIP switches, 3 7-segment displays, VGA and stereo audio output, 39 I/Os (including four PMOD connectors), and USB JTAG. Papilio One $38/65 250E/500E 48 I/Os, USB programmer and serial comms. Eagle board files are freely available. It uses a custom bitstream uploader tool, but it is open source and cross platform. Open Workbench Logic Sniffer $50 250E Borrows its design from the Papilio One and provides sixteen 5V tolerant buffered inputs, and compatibility with the Papilio One's 'wing' expansion boards. Gameduino $53 200A An Arduino shield that is intended to be an audio and video coprocessor for Arduino applications, but could be repurposed as a general-purpose FPGA interface board with the Arduino form factor. VGA and audio outputs, with SPI flash. XuLA-200 $55 200A A very small PCB with USB, a PIC18F, 8 MB of SDRAM, 2 Mb of flash, and user IO headers. It could be used as a plug-in module, or since the design is open source (with Eagle files), as the basis for a custom board (as long as it is also open source, as per the license). MicroNova Mercury $70 200A A breadboard-friendly 64-pin DIP module form factor. It provides 30 5V-tolerant I/Os, 9 other I/Os, an 8 channel, 200 Ksps ADC, 4 LEDs, a switch, 4 Mb SRAM, and programming over USB (with a Windows programming application). JTAG interface pins are also broken out. Digilent Basys 2 $89, $69 academic 100E Four PMOD connectors, PS/2, VGA, 8 switches, 4 buttons, 8 LEDs, four 7 segment displays and on-board USB programmer. Aessent aes220 120 EUR 200AN/400AN A small stackable module that features a Cypress FX2LP USB controller, 128Mb SDRAM, 16 KB EEPROM, 72 GPIOs, 5 LEDs, 2 switches, and power via USB or external supply.

Others:

PLDkit has a number of low-cost boards for older Xilinx parts - CPLDs, Spartan 3, and Virtex 4 and 5.

Lattice

Actel/Microsemi

Name Price Device Notes Microsemi SmartFusion2 SoC FPGA KickStart Development Kit $59 M2S010S FPGA Contains an integrated 166 MHz ARM Cortex-M3. This board provides a BLE 4.1 module, light, motion and temperature sensors, 4 LEDs, three PMODs, Arduino shield support, four RGB LEDs, two buttons, and serial/programming via USB. SmartFusion System-On-Module $62 A2F200 16 MB PSRAM, 16 MB flash, and Ethernet. A Starter Kit is also available. SmartFusion2 System-On-Module $71-$123 M2S005-M2S090 A module with an integrated 166 MHz 32-bit ARM Cortex-M3. On board are 64 MB RAM, 16 MB flash, and 10/100 Ethernet. Also available is a $179 Starter Kit, which includes an FPGA module as well as USB/Ethernet connectors and a prototyping area. Actel IGLOO nano Starter Kit $99 AGLN250 Switches and LEDs onboard, USB-serial, a USB programming adaptor, and what looks like plenty of low speed I/O. Microsemi SmartFusion Evaluation Kit $99 A2F200M3F Integrated 100 MHz ARM Cortex-M3, 10/100 Ethernet PHY and on-chip MAC, USB-serial, on-board USB programming interface, OLED display, 8 LEDs, two user switches, and an indeterminate number of analog and digital outputs. It looks like a very interesting and inexpensive board for developing mixed FPGA/microcontroller applications. Future Avalanche $180 MPF300T Wi-Fi, Gigabit Ethernet, 512 MB DDR3, SFP+ connector with one transceiver lane, Arduino headers including ADC, PMOD connector, mikroBus connector, USB-UART and JTAG, 8MB flash, 2 SPST switches, and 2 LEDs.

Intel / Altera

Cyclone 10

Name Price Device Notes CYC1000 30 EUR 10CL025 An Arduino MKR form factor board with 8MB SDRAM, 2 MB flash, 3-axis sensor, 8 LEDs, 2 buttons, 21 I/Os, and USB Arduino MKR VIDOR 4000 $60 10CL016 8MB SRAM, micro HDMI, MIPI camera connector, WiFi, BLE, Mini-PCIe expansion connector (though no PCIe lanes), SAMD21 ARM Cortex M0+processor, LiPo battery support, USB, and 22 I/Os.

Cyclone V

Name Price Device Notes DE0-Nano-SoC $99, $90 academic 5CSEMA4U Integrated dual core ARM Cortex-A9 with 88 digital I/Os, Arduino shield compatibility, ADC, 3 buttons, 4 switches, 9 LEDs, accelerometer, and USB programmer. The ARM processor is connected to 1GB DDR3, micro SD, USB OTG, USB-UART, gigabit Ethernet, Chamelon96 $129 5CSEBA6U A SoC with dual ARM Cortox-A9, 512 MB DDR3L, micro SD, 802.11 b/g/n, BT 4.1, USB 2.0 OTG, two USB 2.0 host, HDMI out (1080p @ 60fps), MIPI CSI connector, a low speed connector with UART, SPI, I2S, I2C and 12*GPIO and a high speed expansion connector, and 4 user LEDs. DE10-Nano $130, $99 academic 5CSEBA6U Integrated dual core ARM Cortex-A9, HDMI output, Arduino shield compatibility, ADC, 88 digital I/Os, 5 buttons, 4 switches, 9 LEDs, accelerometer, and USB programmer. The ARM processor is connected to 1GB DDR3, micro SD, USB OTG, USB-UART, and gigabit Ethernet. Cyclone V GX Starter Kit $179 5CGTFD9E Packs 4 Gb DDR RAM, 4 Mb SRAM, high speed mezzanine connector with four 3.125 Gbps transceivers, 40 GPIOs, Arduino-compatible header with analog inputs, configuration flash, USB programmer, HDMI output, audio, 18 LEDs, 10 slide switches, 4 debounced buttons, CPU reset button, 4 seven segment displays, micro SD socket, and USB UART. DE1-SoC $199, $150 academic 5CSEMA5F Contains an integrated dual core ARM Cortex-A9. The board has 64 MB SDRAM, 1GB DDR3, micro SD, dual USB 2.0 host, gigabit Ethernet, PS/2, IR emitter and receiver, around 80 digital I/Os, 8 * 12-bit 1MSPS ADC inputs, VGA, audio codec, analog TV video input, four buttons, 10 switches, 11 LEDs, 6 * 7-seg displays, accelerometer, USB-serial, and USB programmer.

Cyclone IV

Name Price Device Notes DE0-Nano $59 academic EP4CE22F 16 Mbit flash, USB programmer, 3-axis accelerometer, 8-channel 12-bit ADC, 106 pins over three expansion headers, 32 MB SDRAM, 2 Kb EEPROM, 8 LEDs, 4 DIP switches, and two push button switches in a very small package. devboards DB_START_4CE10 115 EUR EP4CE10 16Mb SDRAM, 19 I/Os, 5 input pins, 6 LEDs, 2 buttons, and built-in USB programmer. Ordb2a-ep4ce22 149 EUR EP4CE22F A development board that was designed for the OpenRISC processor and comes with a Linux port. It contains 32 MB SDRAM, 1 MB SPI flash, SDIO connector, Fast Ethernet, USB OTG, USB serial/JTAG, and expansion connectors with 62 GPIOs. Also available is an SO-DIMM board with an ARM processor and Ethernet switch. devboards DB4CGX15 153 EUR EP4CGX15BF A reasonably priced PCIe development board with 32Mb SDRAM, 20 I/Os, 4 input pins, 2 LEDs, high speed transceiver I/O via MMCX connectors, and a built-in USB programmer.

Cyclone III

Name Price Device Notes Terasic Altera DE0 $119, 81 academic 3C16 8Mbyte SDRAM, 4 Mbyte flash, SD card socket, USB programmer, 3 buttons, 10 switches, 10 LEDs, 4 seven-segment displays, 16x2 LCD interface, VGA output, RS232 and PS/2 interfaces, and 72 I/Os.

Max 10, Cyclone II, miscellaneous

Name Price Device Notes MAX1000 €22/32 10M08/10M16 A small board with 9 analog inputs (some pins shared), 15 I/Os, 2 buttons, 8 LEDs, 8MB SDRAM, 8MB flash, 3-axis accelerometer, and on-board USB programmer. It has been reviewed by JV::Store. Rysino $37 (approx) 10M04 An open hardware (BSD licensed) Arduino form factor board with 16 I/Os and 6 ADC inputs, USB-UART, 8 LEDs, and 4 DIP switches. Wayengineer $28-77 Cyclone II A range of cheap boards from Shenzhen, most with RAM and a variety of I/O including LCDs, 7-segment LEDs, VGA, switches, etc. Again they're great value if you already have some experience with FPGAs, are comfortable reading schematics and don't require any vendor support. SNO $49 10M16 A tiny board that is designed to be compatible with the Arduino IDE. It has 32 I/Os, of which 6 are shared analog and digital. MAXimator EUR49 10M08 Another MAX 10 board with an Arduino form factor. It has 5V I/O, ADCs, HDMI and VGA output, four LEDs, and micro SD. There's also an expansion shield with extra 7-segment LEDs, RGB LEDs, and buttons. Comprehensively reviewed by Andy Brown EP2C20 core board $62 EP2C20 Another Chinese board of unknown origin with little online documentation, but it looks like good value with one of the larger Cyclone II parts (18752 LEs), 256 Mb SDRAM, 2 Mb SRAM, a USB programming cable, four switches, and 30+ I/Os. Alorium XLR8 $75 10M08 A MAX 10 board that is a drop-in replacement for an Arduino Uno, and comes with FPGA-accelerated hardware components that can be used from Arduino sketches. It features 5V I/Os, Arduino-compatible ADCs, and USB-serial. FTDI Morph-IC-II $110 Cyclone II Contains an FT2232H USB interface chip to provide high speed data transfer. It has a total of 80 to 96 I/Os (split between the FPGA and FT2232H, and depending on who you ask) with a 0.1" spacing.

Anlogic

A Chinese FPGA vendor

Name Price Device Notes Sipeed TANG $17.90 EG4S20 1 MB flash, 64 Mbit SRAM, RGB LED, TF card socket, FPC sockets for LCD or VGA adaptors and camera or ADC, resistive touch screen controller, USB-JTAG, and 72 I/Os.

Others:

Waveshare supply a range of inexpensive ($20-$34) boards for Cyclone II, III and IV. They provide config flash, four LEDs, and a large amount of digital I/O (130-160 pins). An external JTAG programmer is required.

KNJN Pluto ($29-$129) a range of small boards with various FPGAs. No on-board peripherals, so they seem more suited to dropping in to a larger project than as a standalone development tool.

Random Altera boards on eBay. For around $20 to $50 there are plenty of Altera CPLD and Cyclone II/IV boards. They tend to require a JTAG cable (though some even come with one). Many are very bare bones, but some have RAM and extra flash. Probably only recommended if you're already familiar with the parts as documentation is pretty lacking, but good value.

Cypress

Not strictly FPGAs, but a range of interesting reconfigurable mixed-signal devices.

Name Price Device Notes CY8CKIT-059 $10 PSoC 5LP Integrated ARM Cortex-M3 on a breadboard-compatible board with a snap-away programmer/debugger. CY8CKIT-043 $10 PSoC 4200M Contains an ARM Cortex-M0. A breadboard-compatible board with a footprint for a Bluetooth Low Energy module, and a snap-away programmer/debugger. PSoC 4 Pioneer $30 PSoC 4200 Cypress' own cheap dev board offering. Integrates a Cortex-M0 and support for both Arduino shields and Digilent PMods, a CapSense slider, RGB LED, and one button.

Omissions

If you manufacture or know of any other cheap FPGA development boards, please let me know so that I can include them on this list. Review units will be cheerfully accepted! :)

There is a long and comprehensive list of boards at FPGA-FAQ that includes a couple of other cheap options - there are a number of Spartan-3 generation boards that I haven't listed.