Out of all the altcoins OP mentioned I think Ark is the only one I can go with for a long term, there are couple lots of new altcoins now to go with on a long term such as MVL, Binance and Huobi tokens and so many more
I don't like ark project I prefer to invest in waves as it's very very good project if you ask me and also have major developments in the past and they always deliver what they have promised and that too on time, they aren't like other projects that say a lot of things at the time of crowdsale and when it ends they deliver a second copy of a pre existing project.