I personally recommend these and promote them on my sites:
(Posted in order of revenue they generate, your results may vary)
1. True Earnings (CAP Certified Partner)
2. Gambling Wages (CAP Certified Partner)
3. iNetBet
4. Wager Profits (CAP Certified Partner)
5. Casino Paycheck
6. CWC Affiliates (love the support, just havent connected with any big players yet) (CAP Certified Partner)