Three of my 'locals':
Seattle Museum of Flight - very good collection, well presented.
Evergreen Museum, McMinnville Oregon - famous for the Spruce Goose of course, which is alone worth the visit. They also have a few warbirds and transports.
Tillamook Oregon. Go just for the ambience. The museum is in one of the surviving blimp hangars, a huge gloomy building. Leave the camera it home though, it's simply too dark. Guppy Strat outside.