Mike's Liquors
Mike's Liquors has a really nice selection of Tequilas, and coolest of all, they don't jack up the price of a Tequila because it's popular. Mike's sells tequilas right around the suggested retail, regardless of popularity. This is incredibly important to guys like me who love great tequila, but also have a price threshold. The photo submitted (got it off of Yelp) is probably a little under half their selection. The staff is really friendly and the place is clean, and if you're not in San Francisco, you can order online.
Here's their tequila page: http://mikesliquors.com/contents/en-us/d29.html I have no idea how their shipping rates are. I'm lucky enough to work near Mike's.