I think top 3 are certainly not debatable. As per rest, I do like Bittrex but right now I am using
KuCoin, as I put it as a very HOT property not because of the exchange part but because of being a Cryptocurrency themself.
It makes them such highly potential thing, and should be used confidently. At least, I am on for doing that and it really makes me feel comfortable with their reasonable fees and many bonuses as well.