Have to admit, if there's another shop in town that sells discs, I don't know about it. Honestly, even if there was I would still go to Spinner's. You know you're dealing with other people who play and understand the game.
The couple of times I've been there have been outrageously helpful and the guys there are true veterans of the sport. They've been helpful, respectful, and knowledgeable without being cocky or rude.
I drive from across town just to get here, and it's been worth my trip just about every time. Only once have I gone and the young man working the counter didn't know anything about the game or product. Otherwise, these guys are the best!