For now, I'm quite satisfied with the exchange I use - CEX.IO. Why I chose exactly this one? I liked its market, quite vivid and, by the way, is being currently expanded. Also, it's strong security though very exhausting from time to time (if talking about verification process). And I like the idea of providing a separate platform for trading, https://cexbro.com/. Haven't tried it yet, but very passionate about it and planning to test it in the nearest future.