I know that Playgarden in Tribeca makes cleanliness one of its core principles, cleaning the toys three times a day, and they are true to the promise. The toys and space are very clean, but you'll need to take a class and pay for gym time for the privilege. Probably worth it if that's what you are looking for.

City Treehouse is also a membership based playspace, the centerpiece of which is a giant water table with a play stream, and a unique payment structure where you buy play time in batches. Your annual $50 membership per child includes 2 hours of play and then you can buy additional time in batches of 10 to 100 hours. City Treehouse also requires you to reserve play time in advance which means that the play space is never too crowded. It is also very clean, if for no other reason that it only opened this past summer.

Some other play spaces that are newly opened and therefore likely not to be too grimy are:

Nairobi's Knapsack is a brand new indoor play space in Prospect Heights. I haven't been there yet, but it has been recommended by readers Unfortunately this venue has closed.

New York Kids Club has opened two brand new facilities in Battery Park City and Brooklyn Heights.

Which playspaces have you found to be the cleanest? Click here to place your vote for cleanest play space in NYC.