You don't have to go to the rooftop for great views. Sometimes walking the sidewalks is a lot more interesting because you never know who you'll see in NYC. Top right picture you see Central Park West. To the left of the picture you see the Trump International Hotel and Tower. Good people watching here.
Center right picture was taken on a side street in Chinatown. Here you will be amazed that so many people and buildings can fit into such a small space.
Bottom right picture you see the Ameritania Hotel on 54th Street. This is right around the corner from the famous Studio 54 and the Ed Sullivan Theatre where the Late Show with Dave Letterman is located. Great people watching here.