There's a place on the San Antonio Riverwalk that's amazing. Moderate to expensive and like no other place I've been. It's call Dolores Del Rio and has the best food, atmosphere, and music in town. Hands down.
Go to the most popular part of the riverwalk. It's called "South Bank." There's a great bar on the way to the restuarant to have cocktails, it's called "Swig, Martini and Cigar Bar." Then, on the same side of the river as the bar, walk down until you think you've gone too far. Then walk some more and you'll see a small door all the way down on your left. It's across from the La Masion Hotel. You'd never know that it's there, but once you've gotten there, you'll be glad you went.
You walk in, and it's like a cave. The tables are close, but it's small and great for live music. When you go to the back for the restroom, you walk through the kitchen and see that it's clean with lots of love, from the staff, pouring out.
A good friend of mine plays there on a regular basis (he's on his honeymoon right now) and will play sometime soon with his jazz band. They have mixed (but it's usually Italian) cusine with a nice wine list and some of the best deserts.
Laugh, have a great time with everyone else, and remember that's it's truely an original.
Oh, and the owner will belly dance sometimes...that's quite a sight to behold!