Poloniex is worst, no support and breaks down every now and then. Bittrex is clean and glitch free but has high trading fee. Binance covers both aspect but has lower volume right now.
Here's my detailed review:

Coin Marketplace

STEEM 0.72
TRX 0.10
JST 0.075
BTC 57481.14
ETH 4344.51
BNB 617.50
SBD 7.00