Total Wine Alexandria, VA is right off 395, not sure if you'll go around the Beltway, but if you cut through using 295S to 695, to 395, it's very close off the highway, and could save you mileage, just not during rush hour.
In addition to this the one in Springfield and the one in Fredericksburg are also right off the highway.When you get down to Richmond I recommend Once Upon a Vine South and Corks and Kegs. They're not right off the highway though. Mekong is an amazing bar not far off the highway in Richmond if you're looking for a pit stop!
Friendship Wine & Liquors is good. Exit 77B in Maryland, right behind the Wawa and across from the Wegmans. I try to stop there every time I head up to NJ. Apparently there is also a Wine World near there as well, though I've never been to it.
