My top best exchanges:
Bitfinex
Binance
Huobi
Kucoin
Etherdelta
Bittrex
 
Such exchanges as Poloniex, HitBTC and OKEX I don't like. Poloniex did not verify me for 7 months, I stopped writing letters to them and forgot about this exchange. In early 2018, OKEX did not have a translation of the support page in languages other than Chinese, which was a huge problem. On this exchange, I also could not be verified and after 5 appeals I abandoned this case. About hitbts all probably know what kind of exchange it is))))