I live about 20 minutes from it and have been about a dozen times. I got lucky and got to go before it opened. They were having a Salute to Military Veterans (my Dad was an Army Aviator), and Paul Tibbits was there right in front of the Enola Gay.

It's a great museum, and as said before, has tons of room for expansion. The original 707: the Boeing 367-80 "dash 80" is in there, right next to the B29 and a Concorde. Too cool. They also have an IMAX theater, so check the website for shows.

The downside to the museum: parking is $10 per car. So take 4 people with you, and you won't feel so bad about it!

Two other things: The Evergreen Air Museum in McMinnville, OR has an SR-71 that you can actually look into the cockpit.

I'm sad that the Smithsonian doesn't have the first B747. I thought I had read years ago, that it had been donated. But, I think it's wasting away out in the desert. Not sure who owns it...