GameFAQs
Offers over 40,000 video game FAQs, Guides and Walkthroughs, over 250,000 cheat codes, and over 100,000 reviews, all submitted by users to help you.
http://www.gamefaqs.com/

TVG
One of the longest running independent video games website. Updated daily with the latest gaming news, reviews, previews and video game cheats.
http://www.totalvideogames.com/