Oh, I totally forgot about the Evergreen Aviation and Space Museum in McMinnville, Oregon. The "Spruce Goose" along with lots of aircraft and a very, very good Space Museum. I'd put it 4th on my list, ahead of the Seattle Museum of Flight.
Plus, if the rest of the family doesn't share your interests, there is a waterpark right next door, featuring a 747 on the roof (yes, a waterslide is incorporated into the 747).
