Pokerlistings by far.
If you´re talking about the “big” sites why not throw in casino.com casinomeister.com, onlinecasinocity.com, gambling 911
The first two make money through paid ads so that´s a different business model than for most people here but I would say it doesn´t matter as they´re all earning money in the casino industry at the end of the day.
casinocity does both aff and paid advertising I think
don´t know about gambling911
oh and possibly gonegambling.com and got2bet