Hmm... well I loved DC but I was only there for a day trip a few years back.
Only beer place I went to was a brewpub. I can't remember what it was called and beermapping.com is not providing me with anything that rings any bells.
If I remember correctly it was not too far from the Spy Museum though. Some nice beers, a very goo banana bread beer and a lovely dark beer which I think was a stout or porter but it was a long time ago and I was still pretty new to craft beer at the time.