Central Park. With its lovely carousel, a zoo, two ice-skating rinks, and numerous playgrounds and ball fields, Central Park is a children's wonderland.
Bronx Zoo Wildlife Conservation Park. This is one of the great zoos in the world -- and you don't have to be a kid to love it.
Intrepid Sea-Air-Space Museum. Climbing through a retired battleship beats the playground any day. With real planes on deck and interactive exhibits inside, kids are never bored here.