Go to the natural history museum for the hayden planetarium, it's quite cool, but don't do what me and mate did - stand there looking down into the sphere for most of the show, only realising later that it's much more effective if you don't do that!

Like someone else said, the village is cool - the market is really cool at christmas - nice place.

Washington square - just because you see it on TV in films n' stuff! Same for grand central station.

Adrian