If you want great Mexican Food, skip Qdoba (as suggested above; what was that guy thinking?) and head to the intersection of 18th and T Streets, NW. It is a relatively short but scenic walk from the Dupont Circle Metro - Q Street exit. There you will find Lauriol Plaza. I suggest anything with mesquite in the name and more than one serving of chips and salsa. If you want a margarita, order a pitcher as it is more economical. On a wonderful Spring, Summer or Fall evening, I prefer the front patio over the rooftop because the people watching is more enjoyable and it is a little less noisy. Again, sometimes there is a wait, but there is a wait because it is worth it.