If you gave Z any less than 4 stars - you've just never had one of their fab margaritas! My favorite is the Cha-Mango (chambord and mango mixed). But let me not get ahead of myself....
I don't live in a city with a Z'Tejas anymore, so I always make sure to stop in when I'm in Phoenix. Before you go, just note, it's TEX-MEX, not Mexican food. There is a difference and you have to know what you're getting into. My favorite dishes are the baked seafood enchiladas and the jerk chicken salad. They also bring you cornbread (with real corn in it) while you wait for your meal.
Z always goes above and beyond when it comes to customer service, so you never have to worry when you come in - you'll ALWAYS be taken care of!