Leopold’s Kafe and Konditorei, 3318 M Street NW, Washington, DC, 202-965-6005 (Metro Trip Planner - opens in new window) [Washingtonian | WaPo | City Paper | food-plan | Don Rockwell]
Might be OK for Georgetown. The specialty is pastries, they sometimes have Tafelspitz.
Euro Bistro (web site), 314 Elden Street, at Herndon Parkway, Herndon, VA, 703-481-8158 (Metro Trip Planner - opens in new window) [Washingtonian | WaPo | City Paper | openlist | Citysearch | Yelp | Gayot]
Austrian food, with some Thai (!) dishes. Spaetzle.
Cafe Tirolo, 4001 N. Fairfax Drive, Arlington, VA, behind Tara Thai, closed weekends, 703-528-7809 (Metro Trip Planner - opens in new window) [Washingtonian | WaPo | City Paper | food-plan | openlist | Citysearch | Gayot]
It used to be run by Austrians, now it has been sold to Koreans. The spaghetti has more garlic, and the place is not what it once was. A real loss.