The Spy Museum was so worth the price the last time I went! My younger brother also enjoyed "becoming a spy" there as he's exceptional at memorizing information. Unfortunately, however, I did not have enough time to sit down and watch all the documentaries that were provided, but it's definitely worth taking your time on the exhibits. I highly recommend going. As for the other attractions, visiting the different Smithsonian Museums, especially the Natural History Museum, is a must. Make sure to bring your camera!