I just started playing with cryptos, mostly for fun, like 2 months ago, so may not have tried all the exchanges yet. I did like the user interface for CoinEX, and they certainly seemed faster than Cryptsy. And they had an advantage of not listing an insane amount of coins for trading. I wasn't fond of the chat box though... and the scripts they ran (javascript? Not sure what it was) -- guessing that led to the exploit.

Anyway, I am curious what people think are the best exchanges. For me, the best is Cryptsy, even with its issues. These are the ones I have tried:

Cryptorush -- UI looks like it was put together by a 15 year old. Just stuff thrown up there, little coherence, weird buy/sell setup, and feels like it'll fall apart any second.

MintPal -- Nice UI, clean, easy to use. But no idea about security.

CoinedUP-  Terrible UI, low volume, extremely basic.

Atomic Exchange -- supposedly good security, but it sort of reminds me of Radio Shack. Odd layout, weird selection, not many popular items, and high prices. You end up making a small purchase, spending longer than it should to do so, then wonder why you bothered.

Bittrex -- low volume, so-so selection of coins. Iffy UI, at least so far -- missing some basic functions. They do seem to get some unique coins early though.

Poloniex -- okay-ish UI, some unique coins. I kind of like them, except for the fact that they lost a lot of people's bitcoins. And that is rather hard to overlook.