If you're a classic gamer/collector, you gotta go here.
The people here are pretty knowledgeable and helpful, and they have a serious number of games.
It's a cramped space, but you work with what you have, I guess. They have consoles on hand you can try, too! I tried a Virtual Boy for the first time here! It hurt my head. But it's all good, it's still cool that they let you play around/test the games you're interested in buying. Very good stuff, and not usually done at the other stores I've been to that sell used games.
If you're looking for that particular NES/SNES or other old school game, they'll probably have it, and will let you test it! They also have a large selection of strategy guides and other random stuff.