I think it's good not to have your eggs all in one basket in case something unforeseen happens. I'd recommend dabbling a bit in a lot of them.
Bitcoin seems obvious since if there's another split you'd have bx1 and bx2. Also maybe look into bitcoin cash, I think it's undervalued and may take off in 2018...
I think the EOS project is an interesting contender to Ethereum and would recommend it over Ethereum if you are looking at a 2+ year outlook. Eth classic also seems no different than Eth, well, besides the hacker...
Zcash and zclassic along with monero all seem to be interesting privacy centric coins. I don't like dash but can't refute it's staying power and user adoption is important. And last but not least, then I've heard things of decred but don't know much about it.
I'm pairing down my BTC to load up on bcc. I'm hedging that with LTC and dash mining and have some EOS for long term giggles.