Who said that museums are only for works of art? Use them creatively.

The New Museum in the Bowery has spectacular views from its top floor, and the museum is fairly small overall. Intriguing and modern interior make it easy to wander. Great to spend an hour or two.
>> New Museum, 235 Bowery, T. 212 219 1222 The Metropolitan Museum, on the other hand, is great to waste time in because it's so huge and designed in traditional grandeur. You could hardly pay attention to all the works of art if you wanted to.
>> The Metropolitan Museum of Art, 1000 Fifth Avenue at 82nd Street T. 212 535 7710 The Neue Gallerie is right across the street. It's a lot smaller and specializes in German and Austrian artists. Cool contemporary stuff in an old and well formatted building. If you get to the Met and realize you don't have the time or patience for its vastness and/or population density go for the neue.
>> Neue Galerie, 1048 Fifth Avenue, T. 212 628 6200 Matteo A. Tunioli