They have a massive range of the history of aviation with a good mixture of foreign birds as well as US aircraft. I'm personally a fan of those classic Douglas planes, they're so incredibly iconic and have quite a showing at the museum.
EDIT: I guess I should clarify the relation to this article. The actual prototype is housed at the Air Force Museum in Dayton, OH along with the C-97 that carried it on display. They have a small exhibit with some example photos of its technology. Its literally right next to the B2 on display.