DC seems to be teeming with local Thai restaurants, and Sala Thai is in my opinion one of the better ones. I frequented this spot for take-out when I lived in the U St. area and it certainly does the job when a Thai food craving kicks in. I can't say it's amazing Thai food or anything better that you may find in other cities, but it's good. They do have tasty cocktails in their restaurant and often have a jazz band playing at the U St. location, which is also connected to a sushi spot, which is convenient if you're looking for a few different Asian dishes. Take advantage of their free delivery as well, if you live in a close radius to one of their locations. I will recommend their Drunken Noodles and Penang Curry - both are very delicious.
Pros: quick take-out or delivery, solid Thai dishes
Cons: on par with most DC Thai restos