For me the best trading site is the poloniex.com and yobit.net this site help me to make money everyday or every week try to trade this site u will be happy soon.
I think Bittrex is the best compared to both these, as it gives you the best features as well as security, as I have never heard them being hacked ever till date...
Many people also recommend that you have to trade on Yobit and as you can see you see also that it is becoming more popular and more people is going to trade.
And the reason is that they want to have some profit now and that the value is now not rising.