It's appaling, really, how many bad mexican food places we have here in Tucson. If ever you find yourself in a mexican resurant where the salsa tastes oddly like Pace, get out of there!
Mi Nidito, however, is one of the "real" places. It's a little kitshy inside, but the food is outstanding, as is the bar. If you want a good experience (and a long line, head down there)
Now, this next comment might get some people mad at me, but I feel justified it saying it. My husband is a Tucson Police Officer, and he occasionally tells me places that I am free to go during the day, but should never go to after dark. Mi Nidito is one of those places. Not because of the resturant, but because of the area of South Tucson that it's in. Make your own decision