The Pima Air & Space Museum is AMAZING. The indoor hangars are cool and whatever, but outside is an aircraft enthusiast's wet dream. Obviously you get the military fighters and whatever. But you also have experimental designs that never made it to production and quite a few historical civilian planes. For someone like me, it was fucking wild. Going back tomorrow because there isn't going to be rain :D
Oh, they do have an SR-71 and a D-21 indoors, so the indoor hangars aren't all second-fiddle to the backyard.