Hi there websolvent.
The ‘best’ is very much dependent on your traffic and key territories. It is also very much a case of trial and error too. My advice to you would be to try out a variety of TRUSTED affiliate programs on your sites to see which casino/poker/bingo/betting etc brands convert the best, bring you the best player value and make you the most money (and pay out as they should do).
There are plenty of programs on here who can offer that and if you’d like advice on those not listed here, please add me to msn: tomgalanisvc [at] hotmail.co.uk. I am currently working with some excellent gaming brands who I am sure would make excellent fits across your portfolio of sites.
Cheers,
Tom