Heres my picks for 2018 and why:
1. ZCoin- great technology, privacy trend, low market cap
2. ZRX - Interoperability, low market cap, great team
3. Bitcoin Private- bitcoin + privacy= win
What are your picks?
I would prefer ZRX than Bitcoin Private.
Just look at coinmarketcap if the ZRX is ranked 29 and the private Bitcoin is at 110.
But it depends on you to choose.