BlackCoin (BLK) is probably one of the most alive and stable PoS-only coins. Active development and a list of side-projects such as Black Halo for smart contracts (now to be included in Blackcoin core). Reward of 1.5BLK per block. They just updated their wallet to support faster transaction times, faster syncing for fullnodes (you need fullnode for staking) and, as said, smart contract support. They also published a whitepaper (PoS 2.0) and debate in their vivid community to improve PoS technology further.

CoinMagi (XMG) Hybrid PoW and PoS, which is better than pure PoW but still not as good as pure PoS since you still need PoW to secure the network. They are traded on Bittrex.

Mintcoin (MINT) Yes, they are still alive - somewhat. They been once prominent and very vivid but lost alot of this drive. They have a rather high annual interest rate. PoS only. Traded on Cryptonia. I am unsure if their wallet is still developed tho, would stay away as of now.

Nxt (NXT) PoS only with 0.05% annual interest. Build from scratch, active development, exchanges and community.

OKCash (OK) PoS only with a rather high 20% annual interest rate (if this is still true). Traded on Bittrex, small volume, small community. As with Mintcoin, it's not sure if a high interest rate won't rather damage the coin's value on the long run (higher inflation) and as with Mintcoin there been debates to lower the interest rate.

HyperStake (HYP) PoS only up to 750% annual interest rate which seems pretty high for me. Website dead so I can't check further on their annual interest rate and implementation of PoS. Dut still some volume on Cryptopia.

Peercoin (PPC) Hybrid of PoW and PoS. Was actually the first coin who introduced the idea of PoS in a whitepaper, but keeps dependent on PoW for Blockchain-anchoring called process. Traded on many exchanges and different PPC/Crypto and PPC/fiat pairs.

Reddcoin (RDD) Has their own PoS variant called PoSV ("Proof of Stake Velocity") with a 5% annual interest. Traded on Bittrex. Website active.

ZeitCoin (ZEIT) PoS only. Very tiny marketcap of 2m.