I normally go to one of those quick haircut places so I can get in and out, but if you ever want to really treat yourself, go to Menchaca's and get your hair washed.
While they wash your hair, they massage your head. It's not one of those weak fingertip massages; this massage will make your toes tingle.
The haircuts, highlights etc are great, too, but Ohhhh...... the massage. :)