A couple additional thoughts. These are both in Old Town Alexandria

Gadsby's Tavern
http://www.gadsbystavernrestaurant.com/

I haven't eaten here in a while but it was always nice.

Ireland's Own
http://www.pattroysirishpub.com/

A fun place where our group would definitely fit in. The entertainment here is the best in the area.

If in DC, I depend on the local experts as I try not to cross the river. All of Tom's suggestions look good.