I loved the MoMA. It was really interesting and I want to go there again. I had to stand in long line in the rain to get in, though. Another place I also loved and really wanna go back to is the Metropolitan Museum - just the amount and diversity of art they have in there is incredible! Loved it. All the fantastic pieces of art I saw in those places... Oh my God.
The Smithsonian museums of Washington were also enjoyable, and they're free(!), which is really neat.
I adore museums in general.