Bitfinex asserts itself as one of the more dominant platforms in the cryptospace, and for good reason: The highest liquidity on the market coupled with a huge token count really makes Bitfinex your pit-stop to trade almost anything. Their support is pretty good and the FAQ can help both newcomers and more advanced users. Most features require verification but that is also done relatively quickly, compared to other exchanges.
Would recommend Bitfinex to anyone who's serious about trading.