You of course know of this one, but I offer it for anyone else looking.
amazon.com ( associates.amazon.com ) has a huge selection and is the #2 online seller of video games (So says the last update, although I'm not sure who beats them or how it is calculated).
I can't remember ever targetting video games in particular, but I've sold a fair share there, and their name recognition is second to none.
-Allan :gl: