all altcoin are best to invest, but it depends on the users what altcoin their want to buy. etheruem is one of the best altcoin to invest, this coin has possibility grow fast.
indeed the coin that you call is the best altcoin, besides Ethereum there is a good altcoin and can promise the future, it is suitable for long-term investment and its potential is also quite good, namely Eos and Dash. both of these coins tend to follow in the footsteps of Ethereum because in the future technology will become more sophisticated so that it can offset Ethereum, in my opinion for 3 Altcoin this is good in 2018