I really liked Bluejacket Brewpub near the Navy Yard. A good way to spend part of a day is a visit to the Eastern Market weekend street market, then walk down 7th past the Marine Barracks and all the way to Navy Yard. It's a bit of a hike but not bad.
There's a bunch of hipster new stuff on H-Street but I can't vouch for it. Union Market is just off Florida NE near Galludet. It's DC's answer NYC's Chelsea Market. Much of it is very annoying, but there is some cool stuff there as far as food and crafts.
My experience with dives and holes-in-the-wall is dated past a decade. But you might check out Quarry House in Silver Spring (just a quarter mile or so north of the DC-MD line). Chief Ike's in Mt Pleasant/Adams Morgan had a killer reggae night. The Raven in Mt Pleasant was always a reliable neighborhood/dive joint but I think it trends hipster these days. A couple of drinks there would be a nice pair with some Salvadorean chow in Mt Pleasant---I preferred Ercilia's (pupusas and a steaming bowl of sopa de mariscos, ftw).
Another rewarding walk: north on Connecticut from Dupont Circle to Adams Morgan/Mt Pleasant. Make a stop at Keren (Florida/U), a family-run Eritrean cafe---you will know you're in the right when you realize you're the only non-East African there. Jaunt over to Meridian Park aka Malcolm X Park on 16th for some of the best views in the city. Or, stay on Connecticut all the way to Columbia and walk east across Rock Creek Park, or continue north on Connecticut for the zoo.
The best spot in Chinatown is Chinatown Express, where they make the noodles and dumplings by hand in house. It's OK but it doesn't sniff the level of anything in NYC or Chicago.
Great museums and monuments that people overlook: The National Portrait Gallery/Museum of American Art (Chinatown/Gallery Place), National Building Museum (amazing atrium ringed by frieze depicting Civil War Soldiers), Frederick Douglass National Park in Southeast, Fort Stevens in NE (Civil War battle site, with existing earthen works), the Civil War cemetery in NW, and the Japanese American Memorial (between Union Station and the Capitol---ring the huge pneumatic chime, and find serenity in the reflecting pool). Bull Run/Manassas is close by. There's an adjacent winery that's pretty cool.
This post was edited on 3/3 9:20 AM by Anodyne