Best contemporary art museum in NY, have to take a train that goes along the Hudson river (best views during fall season!) / rent a car. This museum only uses natural light, and has pieces from Richard Serra, Judd, Sol Lewitt, Walter de Maria, Robert Smithson, Flavin, all best of the best!
If you are in need of a moment of solitude, this is the place. On my first visit I was in awe of how time seemed to stand still inside. It has now become a sanctuary from the city when I need the pace of life to slow down.