If you are a fan of the movies "El Mariachi" and "Desperado," you might notice that Acuna looks familiar, as both movies filmed scenes there. The famous bar scenes from Desperado were filmed in a bar called the Corona Club. It is not very far from the border crossing. You just cross the border and it's about 2 blocks down on the main strip. They also have a restaurant adjacent to the bar with delicious margaritas.
You simply can't go to Acuna without having a rita or two (which is enough even for us seasoned afficionados, believe me) at Crosby's on the main drag. Good service, a great atmosphere in the sleepy town, and the ritas are superb. Somehow they taste vaguely soapy (I'm assured it's not actually soap), but not in an offensive way.