National U.S. Air Force Museum near Dayton, OH. I've been there quite a few times since it's only about 1 hour from where I live. One of the great things about the museum is that admission is FREE. There are several LARGE hangers full of airplanes dating from the very oldest to the most modern. This is a first class museum, it's absolutely MASSIVE in size and well worth a visit. https://www.nationalmuseum.af.mil/