The one that I personally like the most is gamefaqs.com It's a website that has cheats codes walkthroughs and fourms just in case what you want isn't there so you can ask for it. I've never had a problem finding codes for popular games on it.
I suggest you go to google type in this
"Neoseeker" and "Gamespot"
Neoseeker is a cheat forum and loads of people keeps sending cheats there.
Gamespot has walkthru of the game and it has all the cheats you need and easter eggs and loads more
