Black and White 2 is really great, so if it is the first one he has got, take pompomfairies advice! Basically, it's a strategy game, so if you go to a gaming site you might get some ideas of other strategy games. I personally also like the Civilisation games and I think they've just brought another one of those out although I'm not sure...there's only so many you can play before your life is gone!
It might be useful to know how he plays Black and White, whether he is an evil or a good god. My boyfriend is an evil god and thrives on the military aspect of it, he likes combat and war strategy games like Battlefield and Axis and Allies. Age of Empires is also meant to be quite good and in a similar vein although I've never played any of these games...
If he is a good god well then I'm not sure, I'm a good god but apparently that's because I'm a 'big sissy girl'!!!
Hope that gives you some ideas!