I think Monero leads the pack right now.
Zcash is also useful due to the lower fees.
I think Zencash is also a promising coin for the reasons you mentioned.

But lastly, I think DeepOnion is the one with the most potential to grow. As of now it offers node anonymity since it operates on the TOR network. Even countries like china where TOR usage isn't allowed can use it with OBFS4( TOR obfuscation) which was recently added to DeepOnion. Eventually with the release of DeepSend and Votecentral, it will surely rise to one of the top coins alongside XMR and the others.