Gamewinners was really good for cheats. Gamefaqs is good for chatting.... if you can get past the idiots and the completely anal mods there. CCC is ok, Idc for it. Guru's pretty decent. Never heard of cheat happens
I don't usually go to specific cheat sites but if I had to choose one from the ones I've visited I'd say I prefer CheatCC. Usually tells me what I need to know and more. Depends on what I'm looking for.