Considering that this is the most used blockchain STEEM has a shot in the form of Steem Dollars if somehow it can return to the USD peg (stability is important for merchant adoption). Maybe Bitshares with it's smart coins can gain some real leverage (but the fee model is kind of a roadblock).
I must admit that I am biased to DPOS coins. EOS doesn't exist yet but maybe we could include it (or something built on top of it).
Railblocks and IOTA look promising. I used to be a big fan of DASH but the fee & masternode model are an incentive for holding instead of using it as a currency.