Washington, D.C.

Bars in Washington tend to be concentrated in a smattering of neighborhoods, so it's easy to hop between them to find the best party. Georgetown, particularly along M Street and Wisconsin Avenue, is where you'll find the popped-collar kids and diplomat-brat packs hanging out in preppy and Euro-chic bars such as Maté. The pretty people congregate at Lima and other scene-y resto-lounges along K Street. Lines here tend to be long; book ahead for bottle service to avoid the wait. In Adams Morgan, 18th Street is a something-for-everyone free-for-all, especially on weekends. To get a taste of the madness minus the frat boys, come on a weeknight or opt for classier spots like Bourbon, which has one of the city's best back gardens (not to mention largest selection of whiskeys). The exploding 14th and U Street corridors have the city's most diverse crowd, with Hill staffers throwing back alongside hipster kids and hip-hop heads at places like Café Saint-Ex and restaurant-bar combo Birch & Barley. This is also the place to check out Washington's legendary music scene, with locations like the Black Cat, which Dave Grohl helped found with cash from Nirvana, and Marvin, named for D.C. native son Marvin Gaye, with its rare soul cuts from DJ co-owners Thievery Corporation. For a more chill vibe, grab a glass of wine at Proof, downtown in the Penn Quarter, or score a coveted reservation at nouveau speakeasy Columbia Room.

Washington is a 9-to-5 city, so if you're going out during the week, get started early with the happy hour crowd—things tend to slow down later on. Exceptions include Lima and Eighteenth Street Lounge, which throw rotating parties on school nights; check the Washington City Paper or sites like Brightest Young Things to find out what's happening on a particular night. Weekends are more boisterous, with bars filling up by 11 and going till as late at 3 am. Beware: The Metro closes at 3 am, so head out before last call or risk missing the last train.