El Sombrero is one of my favorite restaurants in town. Its got a nice patio with shade and the atmosphere is pleasant. They have a full bar and a good selection of wines.
The food is also great. My personal favorite are the green enchiladas. I think they make some of the best green enchiladas in town.
The waiters and waitresses are also nice. I've never had any problem at this restaurant. Which is why I keep going back.