Get a good dose of childhood nostalgia for the same price as a subway ride. Central Park's Carousel (near 5th ave & 64th St) is open everyday until 6pm during the summertime and is such good fun! And here's an interesting tidbit:
I learned the first carousel in Central Park was built in 1871 and powered by a blind horse and mule. Why they had to be blind I don't know.
For more information go to: http://www.centralparkcarousel.com/