I'd recommend Next to Normal at the Kennedy Center's Eisenhower. While Alice Ripley's voice may not be in the best shape ever, her intensity as an actor is. The rest of the cast is also excellent.
living in the DC area these days i know what its like to find good stuff...Rock of Ages is playing pretty soon at the national so that should be fun...then theres the obvious kennedy center options of next to normal or wicked...both amazing...and the big news of arena re-opening oklahoma!