My vote goes to TACO!
Just to add my 2 cents...
Tex Tubb's - rather bad Tex Mex; I hate paying for bland, self-serve salsa, and their beans and rice aren't good, so side dishes are out.
Pasqual's - bills self as New Mexican, but isn't like anything I had on my few visits to NM; still has some tasty food, just not as spicy as I'd like.
Laredo's - good, cheap, and great service - I love that I've got chips, salsa and a drink within 30 seconds of arriving.
La Mestiza - very yummy and authentic Mexican!
Taqueria Guadalajara - also yummy and cheap - I need to go there more often.
I know it's my Dallas origins, but there's a special place in my belly for Abuelo's food, too - Tex Mex done well, and another place where I can have chips, salsa and a drink within 30 seconds of arrival. I don't know why Tubb's can't manage it.
Of course being a vegetarian limits some of my options, so YMMV.
Anyone going to talk about Burrito Drive?
Interesting, but not really my bag...
And what about La Hacienda? Their tostadas are my favorite.