When I was a kid, there was nothing better than water balloon fights. I grew up in Brooklyn: we had the fire hydrants, and we would open up a soda can at both ends and squirt people walking by. I love the kinds of things that encourage you to let your guard down, be open and vulnerable, and just to be laughing sincerely.
I've been blessed to spend time with young people and help encourage an environment where it's comfortable for them to be who they are. That's precious for children.