Came here for Adult Swim nights, where the museum becomes 21 and over after hours. There's a DJ with dance floor on the first floor and a cash bar on the second floor. The event is from 6-10pm, and I would definitely recommend coming at closer to 6pm rather than 10pm.
What I loved about the Children's Museum Adult Swim event is that it really brought out the child in me and my guest. We climbed on things, went down slides, finger painted, and ran around pretending to be 8 years old again, while holding a beer in one hand.
I liked the Wildnerness section on the first floor. I'm hoping that the Children's Museum will get a chance to expand to several more floors and incorporate more science-y things. You can also rent out space for receptions and weddings and other events at the Children's Museum. The rooftop garden is an especially beautiful spot with a view of the Capitol building.