National Pastime sports bar & grill at the Gaylord at National Harbor.
It's probably not high on your list of places to check out any time soon - typical sports bar/pub food, lots of TVs and kinda loud - but I have to say the bloody marys here were excellent. Just the right level of kick, and they stuff in a jumbo shrimp.
And a good place outside Nationals Park to root on our ball club.