Sure, why wouldn't Tucson's (arguably) most famous Mexican restaurant also sell its most famous margarita? They pour a fine house margarita (quick note: unless you're currently living in a sorority house, don't let the word "frozen" cross your lips during your drink order), but with a mind-dizzying array of tequilas, juices and other additions to choose from, you can try a different style every week for a few years. Actually, that's a really great plan. We'll see you down there.
Runners up:
2. Guadalajara Original Grill
3. Café Poca Cosa