I have to put my vote in for La Hacienda II on Bannerman Road on the far northeast side of town (directly south of Killearn Lakes). I grew up in the midwest, lived in the west for 10 years, and travel frequently to Texas/California. I have to say that this restaurant comes the closest to the food I have enjoyed in restaurants in those areas over the years.
If you go, though, don't order the standards (burrito? yawn.). Try their chile rellenos with shrimp, and maybe a side order of taqueria style tacos carne asada (grilled steak) or tacos carnita (slow-cooked pork). They will also serve you tacos de lingua (tacos with beef tongue) if you ask, for those of you who are daring. Their outdoor deck is also the greatest in the summer time.
They are pricier than the others in town, but to me they are the most authentic.
What are your thoughts?