I only have a choice of about a dozen at my preferred exchange but the more I look at alts, the less distinct and more replaceable thy become in terms of investment. As the market is rather irrational, planning to hodle for months on a rational basis seems irrational, too, and day trading becomes the most viable option.

As everybody who can, will have their own coins (states, institutions) eventually, and as tech might get stolen or bought and end up in different products, it seems optimistic to assume that a product that's available today will last for years to come. In the months to come, I would watch ETH, Monero, Dash, NEO and Stellar, and sure, also IOTA, Cardano and Verge.
I may at times buy some BTS or STEEM once Haejin talks it up here, too ;)

I'm not really interested in the smaller cap ones because the pumps can be so surprising, that only irritates me. I even had a disillusioning EOS experience where I just couldn't take profits because I was unable to sell (for Bitcoin, there was a run on Bitcoin, while lots of other people also wanted to sell EOS, and the market for that was tiny). Such things should be taken into consideration.
In doubt, day-trade the big ones.