This place has been tagged (in both the Post and City Paper) as the second coming of the Cal-Mexican taqueria in D.C. I visited last week. My impression was that I'd eat there a lot if I worked 2-3 blocks away, but that it wasn't something to go out of the way for. Did I hit it on a bad day? What's your opinion.
For those of you in Arlington, there's a little taco stand in a small shopping center on the right hand side (definitely there on the weekends, not so sure on weekdays), right turn off 50 and across the street from the entrance to Fort Myer - I think it's on Pershing (??? - don't get out there much anymore since my car was stolen in Dec) and I'm more downtown anyway.
I generally pick up 3 tacos de Barbacoa (barbecue, lamb) or Lengue (beef tongue) and a Senioral (non-alcoholic sangria) and head over to the Marine Memorial grounds for a picnic. The double shell soft tacos are stuffed full of onion and cilantro and you can order them picante or mild. MMMMM! Check it out. For my money, that's as authentic as it gets in D.C. If anyone can help with the street name, that would be appreciated.
I live about two blocks from this place, and I eat there a couple of times a month. I think it's quite good (try the frijoles charros, beans stewed with little bits of meat). I don't think I'd get in my car and drive 45 minutes to get there, not because it isn't good, but because there's probably a decent Mexican place closer to where you are. However, if you find yourself near Del Ray, check it out.
Other good restaurants in my neighborhood: Evening Star Cafe (Mt Vernon Ave), upscale neo-southern food in a friendly atmosphere with prices that won't kill you; Monroe's (Commonwealth Ave), neo-Italian, again a very comfortable place for the upscale menu (and outstanding wine list); Calvert Grill (Mt Vernon Ave), good "bar food" with daily specials; Bombay Curry Co, truly excellent and inexpensive Indian food (next door to Calvert Grill).