According to Wikipedia, "Proof-of-stake (PoS) is a type of algorithm by which a crypto currency blockchain network aims to achieve distributed consensus. In PoS-based crypto currencies the creator of the next block is chosen via various combinations of random selection and wealth or age (i.e. the stake). In contrast, the algorithm of proof-of-work (PoW) based crypto currencies (such as Bitcoin) uses computationally intensive puzzles in order to validate transactions and create new blocks (i.e. mining).

At the investor point of view, staking can boost the profits apart of coin market value . Proof of Stake systems can replicate a loan with periodic payments just for hold a specific altcoin. Some coins require to keep his wallet online to stake. Others to lock his coins for a specific time span. Despite the technical differences between systems, some key points should be considered:

Energy consumption, if you are staking in your own machine or wallet

Opportunity cost, if the staking process locks your coins

Relation between inflation rate and staking ROI

The stakepool fees if you are staking in a pool.

Minimum amount of coins needed to stake.

The Full List

Next table shows the summary ROI's results and some additional info. Coins without calculators, no explicitly documentation or with no published ROIs were dropped (*).

Position Altcoin Minimum to stake ROI (yearly) Related info 1 Decred ~80 at the posting moment ~30.00% https://docs.decred.org/mining/how-to-stake/ 2 Stealthcoin No minimum 20.00% https://www.stealthcoin.com/ 3 Ark No minimum 10.90% http://calculator.reconnico.com/ 4 Neblio No minimum 10.52% http://nebliostats.com/calculator.php 5 Okcash No minimum 10.00% https://neotogas.com/ 6 Dash 1000 8.40% https://okcashblockhalf.com/ 7 Neo No minimum 4.80% https://neotogas.com/ 8 QTUM No minimum 6.53% https://qtumexplorer.io/qtum-staking-calculator 9 Reddcoin No minimum 5.13% http://jsfiddle.net/yE6Vp/15/ 10 Pvix No minimum 4.80% http://pivx.cryptonode.co/ 11 Vericoin No minimum 2.34% https://www.vericoin.info/interest.html 12 Stratis No minimum 1.46% https://www.stratispool.com/

Top Five

Here, the top five coins are presented. Only gross ROI are presented, and almost all can be easily found in the web (a table with all coin websites are presented). Let's see the winners:

1 - Decred : 30% p.a.

As reported by this post, the mean ROI in 2017 was 30%. You can stake using available stakepools or running one by your own. Stakepool's fees varies from 0 to 5% over profits. The ticket price is variable.

2 - Sthealtcoin: 20% p.a.

No minimum amounts to keep. There are scarce info about POS and the staking ROI is presented in the main project's page.

3 - Ark : 10.9 p.a.

The maths behind computations profitability of Ark are complex and no calculator are available at publishing time of this post.

4 - Neblio: 10.52% p.a.

No minimum required. The project's page has a easy to use calculator.

5 - Okcash: - 10% p.a.

No minimum amount required. This ROI is just for the first year. After one year staking it will be limited 5%.

(*) They were Waves, LoMoCoin, Espers, Hyperstake, Blakestar, Shift, Cardano (to be anounced), Rise, Pink and DeepOnion.