Coney Island is the best for everything - the beach, the rides, the beer - but mostly for the Skee Ball. It's incredibly addicting, affordable and satisfying (depending on your aim).
Strand is a castle of books. It claims 2.5 million new and used books, across 18 miles of shelves, cared for by 200 employees—so set aside a couple of hours. Plenty of art books and good prices. Get your healthy huff of that old book smell.