It's too bad you're not making it farther north; Maine has, IMO, the best brewing scene on the east coast, and 2 of the premier beer bars in the country in the Great Lost Bear and Novare Res. ( http://www.novareresbiercafe.com/
Some premier east coast breweries:
Allagash (ME; wide distro)--their wit (Allagash White) is widely available, but it's really worth trying any of their other beers that you can find.
Cigar City (FL; has NY distribution)
Maine Beer Co (ME; limited New England)
Brooklyn Brewing (NY; wide)
Ommegang (NY; wide)
Portsmouth Brewing (NH; wide)
Clipper City (MD; regional)
Flying Dog (MD; pretty wide)
Troegs (PA; wide)
Victory (PA; wide)
And, of course, the ever-divisive Dogfish Head in Delaware.
In DC, Churchkey on 14th is probably the best beer bar in DC at the moment http://www.churchkeydc.com/
. Their beer steward (Greg Engert) is really great. Rustico in Alexandria is a viable alternative if you're not in the city proper (Greg also does the beer buying for them, they have a similar though slightly smaller selection--no need to visit both of them), and if you're down that way but stuck in Old Town, Bilbo Baggins has a reasonable selection as well ( http://www.bilbobaggins.net
Brickskellar is overrated, IMO; it was a god-send when it opened as the only place with a wide selection, but there are much better options these days and it usually doesn't have more than half of what I try to order. RFD is the same ownership as Brickskellar but much nicer with a lot more taps; it's worth a visit.
Other highlights along the way:
Max's in Fell's Point Baltimore is a definite must-visit ( http://maxs.com/
Monk's Belgian Cafe in Philly should also be on the list ( http://www.monkscafe.com/