Honestly, DC doesn't have great tex-mex either for the most part. Generally though, the ingredients are higher quality and fresher than what I've found down here. In Alexandria, we will go to the Austin Grill, Los Tios (in Del Ray) and Taqerio Poblano (Del Ray). All are very different from each other. Taquerio Poblano seems to have the most ups and downs. Los Tios lost a step when they expanded. Austin Grill (in Old Town) isn't amazing, but generally reliable. I think I'm spoiled after my visit to Austin last year.