I quite like Alexandria for a place to go for dinner and drinks. Take the Metro blue or yellow lines to King Street station. King's street goes all the way down to the Potomac. It is a very pleasant walk and quite safe. There is an Irish Pub along the street. Down at the end on the river I prefer the Chart House Restaurant as you can sit and watch the Reagan National arrivals ( or departures depending on which way traffic is flowing ). They have some good beer selections as well.
Typhoonpilot