Nuevo Leon Restaurant on East 6th Street in Austin offers inexpensive, and surprisingly good, Tex-Mex in a distinct and memorable hacienda-style restaurant.
Admittedly, the restaurant isn't in the best neighborhood, but you don't go to East Austin for the exclusive gated community experience. You go for the authentic experience and the good food.
It's only a couple blocks south of the Texas State Cemetery and makes a nice lunch or dinner break if you're planning a visit to the cemetery.
The restaurant sometimes gets mixed reviews, and although I haven't eaten here extensively, I've yet to have a bad experience myself.
It's a family owned operation since 1982 and features large indoor eating areas, a special event room, and (recommended during rushes when it can get rather loud inside) a pretty cool patio with a view, depending where you sit, of either the Austin skyline or the metro rail.
In a way, during off hours at least, Nuevo Leon reminds me a little of Matt's El Rancho on South Lamar. It's not exactly formal, but it's not kitschy, ironic, or over the top either like more popular Austin Tex-Mex establishments such as Chuy's or El Arroyo . Maybe it's the traditional family feel that the place has.