Tezos appear most innovative given their focus on formal verifiability.  Given how the reentrancy bug gave us TheDAO episode, Ethereum and Solidity likely remain at risk of crypto geeks figuring out that OCaML/Michelson, as used in Tezos, precludes such bugs. 
NVO is interesting in the DEX space.  https://nvo.io
I don't think it's yet a world-beater (maybe one day....), but I have sentimental favour to Zen Cash too.