Bittrex. Has similar volume, though slightly less than Poloniex. They trade the same top 20, but Bittrex adds more lower-cap coins.
Also, I'm very pleased with Bittrex right now as they said they will support BTCC (or BCC or BCH whatever they're gonna call it) on August 1st. The have not said whether it will be tradable right away or ever. They're still deciding.
Thanks for your reply! Sounds good. I won't trade high volume (my budget will be 1BTC or even less), so slightly less volume than Ploniex won't hurt me. I have also not read something bad like issues with withdrawls about Bittrex yet.