I mainly use Bittrex because it's the leader for pump&dump; moreover Bittrex has a very clear interface with volume, trade history, spread, change and many other useful infos.

On the other hand, Bittrex has its defects as the coin-removal ( if one coin doesn't reach a volume of 0.1 BTC ) they will remove it. Furthermore Bittrex doesn't have a referral program.

But, anyway, for me it's currently the best exchange.