My favorite programs are
Vegas Affiliates (but I don’t like their problems with new stats and 3 days delay),
MainStreet – I have good players there and they accept US players
Gambling Wages – especially I like their Casino Club Player. and they accept US players.
Pearl Gaming – I like their centralized statistics and their promotions for affiliates.
Best Casino Partner – it worked for me very good and I received commissions from them on time via Wire Transfer and without any fees (I was impressed be it). Now I don’t have success with them but I’d like.
I don’t tell you the worst affiliate program (I may do it only in the private section of GPWA), because they pay me money for the advertisement but I don’t have any conversions there, it’s fantastic and unbelievable.