Not too long ago, someone downloaded the 3 billionth Add-on for Firefox. 3,000,000,000! That’s a lot of add-ons (and a lot of zeros to type!)

These eight add-ons are the best of the best. They’re the most used, and with good reason. Let’s count down to number 1.

#8 – With over 1.9 million daily active users, DownThemAll kicks off our best-of-the-best list. It’s the first and only download manager/accelerator built inside Firefox! It features an advanced accelerator that increases speed up to 4x and it allows you to pause and resume downloads at any time, and puts you in full control by customizing your download experience.

#7 – Earning just over 2 million daily active users, Personas Plus is next on our countdown. Personas are free, easy-to-install “themes” for Firefox. Personas Plus extends that built-in functionality to give you even greater control and easier access to new, popular, and even your own favorite Personas. Installing the add-on places a small “fox mask” icon in your status bar or add-on bar which, when you click on it, pops up a menu where you can select, change, or even randomize your Firefox Persona.

#6 – Just over 2.1 million users per day puts NoScript at number six on the list. This tool provides extra protection to your Firefox from security vulnerabilities. It allows JavaScript, Java and other executable content to run only from trusted domains of your choice, for example, your home-banking web site, helping guard you against certain types of attacks.

#5 – Next up, with over 2.2 million users per day, is Download Statusbar. View and manage downloads from a tidy statusbar – without the download window getting in the way of your web browsing. The fully customizable interface auto-hides when not in use, allowing full control without interruption.

#4 and #3 are favorites for the developer fans of Firefox. Greasemonkey and Firebug have over 2.8 million daily users and over 3 million daily users respectively. Greasemonkey lets you customize the way a web page displays or behaves, by using small bits of JavaScript. Firebug is a favorite because it lets you edit, debug, and monitor CSS, HTML and JavaScript live in any web page.

The #2 spot, the best of 3 billion add-ons runner up, is Video DownloadHelper DownloadHelper is a tool for web content extraction. Its purpose is to capture video and image files from many sites. Just surf the web as you are used to, when DownloadHelper detects it can do something for you, the icon gets animated and a menu allows you to download files by simply clicking an item.

We’d like to offer up a special congratulations to the #1 most-used Add-on, with over 13.5 million daily users (and more than 166 million total downloads), and that award goes to Adblock Plus. Firefox fans love it because it gives them control of how they view the web. One reviewer explains “Adblock Plus is one of the reasons I use Firefox, both mobile and desktop!”

And there you have it – the most-popular Firefox Add-ons. (Read more about the 3 billionth Add-on download and see an infographic here.) As Firefox heads for 4 billion add-ons downloaded, will new favorites bubble to the top? Start downloading your favorite Add-on to help it move to the leaderboard – find one here.