To be honest, I quite like freebitco.in's gambling option, check link: www.freebitco.in, although I know they aren't an actual gaming site but a faucet site. Their High/Low game option i awsome, one of the best out there actually, and you can play with the satoshis you earn every hour from the faucet. This means you can easily come out with a major win without ever depositing a single satoshi.

There are several other great sites, like the one I'm currently promoting, but as always play responsible and don't play with money/BTC you can't afford to lose.