The Museum of Aviation at Warner Robins AFB is a really nice medium sized place. There are some real unique displays there, like the RB-69. If you are ever in the Sevierville/Pigeon Forge area, check out the Tennessee Museum of Aviation. Not a large facility, but worth a walk through. A good number of the display aircraft air maintained as flying examples. It is the home of P-47D Hun Hunter XVI, P-47D Wicked Wabbit, and A-1H Skyraider Lieutenant America to name a few.