Upscale Tex-Mex Restaurants?

Let me start by saying that I love a good hole in the wall Tex-Mex spot (shout out Teotihuacan), but sometimes a situation calls for a more upscale option. I've been to El Tiempo, Pappas, and Armandos. Are there any other restaurants in the area that give a more upscale vibe but still serve classic Tex-Mex?