if your going to stick with a single coin for long term investment. Litecoin would probably be your best bet for now. But understand the risks of investing into a single coin, if it flops all your investments are gone.
Alternatively you could buy Etherium and buy tokens with Etherium, this way your much more diversified.
Thats my opinion anyways.
Good luck!
Beercules
Great advice! Definitely want to have my hands in both. Thank you!