J. Hood Wright Park
173rd & Ft. Washington Ave.
The Ancient Playground
East 86th & 5th Ave.
This website has been pretty helpful in my search so far.
I've heard the "Hippo Playground" on 91st and Riverside is the best in the city... That's next on our list to visit. We'll just have to see if it meets my requirements!
(and I'm sure the "requirements" will quickly change as soon as Noah starts walking!)