I have an account in Binance and hitBTC now, these two trading site was my favorite site to trade. There are also Bittrex, Poloniex, Kucoin and Crytopia.
So far for 7 months using these sites now i don't have any problem in trading they are having high volume coins to trade, also very easy to use even though you are a newbie in trading. They are having a friendly admins every time you can contact them for assistance. A large population of investors they have. So if you choose which site then enjoy trading.