I don't know your food budget but there's a good, interesting place near Lourmel, one Metro stop from Ballard. It's L'Os a Moelle, which serves a 6 course (small portions) tasting-type menu for 38 Euros a person, which is a great deal (remember, that includes tax and tip, but not drinks). Here's a write-up and you can Google for others:

http://www.markbernstein.org/Apr0501/LOsaMoelle.html

They only have two selections for each course, but jump in and try real French food. Don't confuse this place, the restaurant, with Cave de L'os a Moelle acrosse the steet, which is a wine bar with simple food served at communal tables.

L"os a Moelle has 2 seating nightly, and you should have your hotel make a reservation for you (unless you're French fluent).