Once you are done with the museums on the National Mall, try to spread out a bit on your museums in the capital. Here are a couple of excellent suggestions:
Phillips Collection. The Phillips Collection is one of those small painting museums that you will fall in love with. It includes quite a lot of American modern painting, but also some of the Europeans classics, as is Renoir’s famous “The Luncheon of the Boating Party”. There is an entrance fee only during the weekend.
Spy Museum. The Spy Museum guides you through the history of spying and is a fascinating tour through gadgets, events and characters. To make things more interesting, you receive an identity at the beginning, one you have to carry different challenges of your visit and remember it at the end.
National Zoo. Everything from pandas (although one of them will make its way back to China in 2010) to seals, from large felines (lions and tigers, oh my) to big apes (and the gorillas are just spectacular to watch and understand why they are so similar to us humans).
Renwick Gallery. This is a museum of American craft, but it is more interesting for some of the temporary collections it hosts, as was one by L. Tagliapietra, renowned glassworker. It is close to the White House, so if you do pass through the area, it’s worth 30 minutes of your time for a quick glimpse (again, also free).
Corcoran Gallery of Art. The oldest art museum in Washington DC, it focuses on American art, but includes some incredible works by Picasso, Renoir and Andy Warhol.