Kotaku heard a rumor that Best Buy is flirting with the idea of selling used video games  in their store, to which I say: woohoo!
Supposedly, the chain will try it out in a few stores as a test, and assuming that all goes well, you may have another outlet to buy used video games from.
Personally, I tend to buy games new by virtue of the fact that I need them immediately, as soon as they come out. However, if I'm just browsing the shelves for a few new games, I love scooping up a few used games to have.
What about you? Do you supplement your game collection with used games, or stick to buying them shiny and new?