Monero
Monero is a good coin with good community. There is a future for all privacy-oriented crypto coins because Bitcoin will not go fully private. However, Monero and Zcash are the most popular. Bytecoin and Verge are interesting but I think people behind these coins just wait to sell all of their coins.
The successful altcoin should had a solid HODL community
The successful altcoin should had a solid HODL community