Binance
ChangeNOW
Bittrex
HitBTC
SimpleSwap
i agree with binannce but the rest i am not sure. binance has a large volume.
there are even many new coins listed there then pumped quickly.
Binance is best because most of the coins listed in the exchange has some potential and seems very active developments from the team. I hope binance is one of the best exchange platform for cryptocurrency trading and same with the bittrex but I don't have much positive about the bittrex.