Possibly my favorite place for Mexican in the Madison area (and worth the drive, even from the west side). From a girl who studied abroad in Mexico and is crazy picky about Mexican food, it's a tough designation for me to give.
The service is always friendly. I could literally drink the salsa--so good. I normally get the chorizo/chicken type fajitas and even the next day as leftovers they're awesome. The rice and beans are just better than average, but really they're just about the same everywhere.