I LOVE King Street Blues in Alexandria - its right at the intersection of King Street and North St Asaph. Really fun blues-y atmosphere. You can occasionally catch local bands there too.
I've also heard good things about 100 King Restaurant for their brunch, and $10 all you can drink Mimosas

Other restaurants I like: Bilbo Baggins, Gordon Biersch, Joe Theismanns, Union Street Public House, and Mango Mikes.
As for something fun to do if you've done the monuments, etc before, and from past posts I think you're into history, are some of the local ghost tours. I don't believe in ghosts for a second, but my mom and sisters go on these, and always find them really interesting.