I would also suggest Monero. It has some real innovation and the dev team is quite capable I think. Moreover its already famous and quite attractive to use for illegal business, so I think this gives the coin some potential to grow in value.
I strongly agree with Fleamint view. Monero has some very important features like as it's privacy; that is, the transactions of a user are not publicly visible on the blockchain. In addition, is untraceable because of ring signatures where is not likely that a transaction could be used to identify a person. At last it is not linkable due to two public keys (spend and view) the monero protocol creates, where only the public spent key is linked with the corresponding private view key of payment receiver.