You should probably go here. They have a huge, cheap menu of Jalisco and Tex-Mex favorites. Right now I am all about the Mexican flag enchiladas and the combo plate (enchilada, tostada, flauta), but they also have the Super Burrito, which is only like six bucks and is bigger than my forearm, no lie. I am also partial to their tortilla soup.
It is not the best food in the world, but it is inexpensive and plentiful and amazingly satisfying after a day of yardwork or a morning of hangover. The staff is very nice, they serve micheladas and horchata, and their refried beans are just straight-up stupendous, creamy with lard or maybe pork fat.
It's fun to eat there because the building is so freaky. We heard it used to be a Chinese restaurant and is therefore shaped like a lotus flower, but I read somewhere else it was first a coffee shop that was designed in the Googie style, which seems like a slightly more plausible explanation for all those parabolas.
Either way, it stays warm in winter and cool in summer and is the only restaurant close to our house that I never roll my eyes at when Eric suggests it. It's on 290 East, just off I-35, in front of the EconoLodge, and you should go there if you do not hate food.
Update, 12/1, 12:43 p.m.: Aha! Check it out in its former modernist glory as the restaurant for the Cross Country Inn. And then futz around on the Austin Postcard site, for it is fun to do so.