When I was wanting a quick fix on some slots and trying to deposit with some of my BTC, I read some of the reviews on this
Bitcoin Casinos site. Some of the reviews go quite in-depth. Obviously you need to be careful when choosing a casino and depositing with BTC or any currency for that matter, you need to make sure they are licensed, you don't want to be losing your money to some shady operation.
Ones I can recommend off the above site that I have played at are mBit and 7Bit which appear to be both managed by the same company. I had a good 2 hour session on Aztec Magic and some Blackjack and managed to cash out 0.066btc which was processed pretty much straight away, having not really played at many casinos that accept bitcoin I was pleasantly surprised at how quick it was.