Not too long ago, I was in Texas for four days, and managed to eat beef fajitas from Lupe Tortillas seven times. And that is from a Texan-turned-New Yorker who is edging closer and closer to vegetarianism—they are just that good.
I love Tex-Mex restaurants in the Lone Star State, first and foremost because chips and salsa are always free (except at Chili's—but they don't count), and you can have as much as you want. But Lupe Tortillas adds in a bowl of charro beans as a kicker. Absolute perfection.
I don't care if you don't eat red meat: get the beef fajitas. You won't regret it. The tortillas are made on site and come hot off the press—so good that you'll want to save enough room to just enjoy a tortilla by itself. Fixin's aren't additional either—you get the whole gamut: pico de gallo, peppers and onions, shredded cheddar cheese, sour cream, and mouth-watering guacamole. There are about 10 locations in Houston; whatever you do, just make sure you get to one of them.