Taco Bamba Vienna, web site, 164 Maple Ave., Vienna, VA, 703-436-6339, note they open at 8:30 a.m. and thus are a breakfast option. (Metro Trip Planner – opens in new window) [WaPo | Washingtonian | TripAdvisor | Ylp | Zagat]
If you read this guide, you probably already know the superior tacos of the original Taco Bamba outlet in Falls Church. The newer branch is yuppified, with longer lines, and the menu is broader, with more kinds of tacos, chilaquiles, tortas, and more sides. I was suspicious, but there seems to be no diminution in quality and a much bigger selection. Definitely recommended. Note that ordering a single taco here gives you much more food than in any other tacqueria I’ve seen, decide accordingly.