If you just landed in San Antonio you'll be happy to know you can even eat pretty good Tex-Mex at the airport. It's not hard to find, but if you're looking to maximize on those cheesy calories, then you'll want to keep reading.
La Fonda on Main is a fantastic option for first-time visitors unsure of the ways of Tex-Mex, as it's on the high end of the spectrum and offers dishes made with clean, quality ingredients. They offer lovely daily specials, which you can enjoy on their gorgeous patio while sipping a superb, freshly-made margarita. Their chips and salsa alone are worth the trip.
Paloma Blanca is another family favorite for upscale dining. From ceviche to nachos, you really can't go wrong here. It's a great choice on a sunny day, as they have a large covered patio.
If, however, you're looking to get down and dirty, don't be afraid to head to Tito's in Southtown or Panchito's on the north central side of town. You'll find all the Tex-Mex classics here from enchiladas to tacos and more. Just make sure to go on a cheat day!