for me, i use poloniex. there are many altcoins with good volume. what i like from poloniex is many altcoins that will got pump and high jump in suddenly. if you don't believe, just see the rate of the altcoins, and see some of altcoins that not famous, become to jump in high rate and its make a good profit.
And you must add another markets are like bitcoin.co.id, bitx.co, quoine.com, triv.co.id and another exchangers who accept IDR (Indonesian currency) without them, although you got much profit, you can not make withdrawal.