All alts which announced their real progress, tech development we should to buy.
One the the promised still Binance coin because of the Binance DEX and blockchain platform
Also would recommend Pundi X with their great terminals
Litecoin is good way too
There are many different altcoins that had a great potential and good performance in the market, it is hard to say on what is the best altcoins in 2018 because of what happened in crypto market are in the red zone now.