Bangkok 54
Bangkok 54, web site, 2919 Columbia Pike, Arlington, VA, 703-521-4070 (Metro Trip Planner - opens in new window) [Washingtonian | WaPo | City Paper | Don Rockwell | openlist | Yelp | Gayot]
A reader recommends. I have yet to go.
Across the street from Rincome Thai.

Fried Soft Shell Crabs

Penang

Pad Cha from the Sea

Mango Sticky Rice