
Guarapo is great -- it's convenient (right on the Court House metro stop across from Wendy's, you can't miss it), it's hip (house music, good-looking patrons, a lounge area), and it serves hookah AND alcohol. The menu also has interesting Latin American fare to order with beer, like empanadas, ceviche, fried plantains with guacamole, and arepas, stuffed corn cakes.
The only downfall is that it's a bit pricy. The hookah is 20 bucks, the food clocks in at 12 dollars a plate, the drinks are another story. The service is also painfully slow (I waited 40 minutes once for my hookah to arrive), but you're really paying for the atmosphere (it's one of those places).
There's dancing on the weekends, including flamenco and salsa, and live music on the weekdays.