My favorite place on Bedford Avenue, this bookstore has both new and used titles. If you're patient and look close enough, you can usually find a book that's worth more than they're asking. Not to mention their stellar selection of magazine titles. Good for design, art, photography, sociology, fiction, and everything in between.
I love that there's a museum dedicated to American art, founded at a time when American artists were underappreciated. The exhibitions are curated with a broad but discerning eye, and the architecture is spectacular. In my experience it's typically much quieter than the obvious choices like the Met and the MoMA - although both are remarkable, there's something I love about the scale and style of the Whitney.
Giant dinosaurs. And the rest of the museum is great if you also like giant whales and outer space and especially the life size dioramas of animals and cave people, which might be the very best Art in all of the city. Sigh.