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...
Hey the best trading site is yobit.net and poloniex.com. because this site are more coin to trade and very safe . not other trading site the coin is very little and not sure it is safe or not