We have several relatives in the DC area, and I always take in a museum or two when we're there. The Udvar-Hazy is a must, as is the Smithsonian downtown. I've been thru the Marine Museum at Quantico twice; one of my wife's cousins is a guide there. Looking forward to the Army Museum on the next visit - thanks for the heads up! 

Yeah, thanks Tojo for the head's up! It's about a five hour or drive here, will have to cruise up and check it out next year. The website looks really impressive!