Large and very impressive USS Midway Aircraft Museum is a must see thing even if you're not a military fan. There is a huge flight deck with real planes, jets and helicopters, real naval aircraft carrier that served in the United States Navy for 47 years. I couldn't stop taking pictures so here is only the "small part" :)
You can actually walk into and even sit in the cockpits of some planes!
I loved wandering through the ship, climbing and touring the various levels, imagining the way things were when it was not dry docked. You need plenty of time to wander the ship as it is much larger than it appears and there is tons of things you need to see!
And don't forget the amazing view :)