There are 2 places in town that serve Tex-Mex (quite different than Mexican food) that I know of.

Salsas in the Marriot hotel and Three Peppers across from the airport.

They are quite different dining experiences. Three Peppers serves Tex-Mex and Chinese food and is a very small place. It has 6 tables and does a lot of take-away business.

The Marriot is a more festive ambiance and you pay for that. You can get a Corona beer there though!

Read the restaurant reviews here on QL.

I, personally, like hole-in-the-wall places that sell decent food at very reasonable prices.