I think the best coins to get involved with in 2018 are going to be privacy coins and coins that focus on faster transactions with big block sizes and perhaps even zero fees. Basically the things that bitcoin struggle with other coins will pick up the slack and these coins will do quite well in my opinion.
Following on this, I feel like DeepOnion and Komodo have large growth potential, both privacy coins (although deeponion is a much smaller market cap), so I'd try either.