That is, I'm seeking to expand my knowledge of bars with both well-selected and extensive lists of wines-by-the-glass. Good food, it goes without saying, is a big plus. I've been very impressed by Dino on both counts. Poste always has very good WBTG picks, though a limited list.
Any other favorites? (I know about Grapeseed; I'm really looking in the District proper, though if you've got something really to rave about in the burbs, well, rave away.)