An awesome, and sometimes free, ferry that links Manhattan at the Financial District to Ikea in Brooklyn via Red Hook. Very great views of the city and if you end up having to pay it's redeemable for a monetary discount towards an Ikea purchase. I think of it as a treat and an investment.
A legendary basketball court in the West Village that is a popular destination for basketball aficionados, deflated hoop-dreamers, and gawking tourists.
Apart from Dia Beacon, in Beacon (upstate New York about an hour away from Grand Central Station) and also the Judd Foundation in Soho, this institution is absolutely one of my favourite places to visit and it is located in Long Island City, Queens. It showcases sculpture in the broadest sense and has an incredible building that used to be a workshop that refurbished and fixed subway cars. It has been running since 1928 and when you visit you will definitely see why that is.