Since New York is an island, one of the best ways to see the city is by boat. They leave from the South Street Seaport, Battery Park, and at the West Side Piers. If you have kids the one hour ride will get you right next to the Statue of Liberty. If you have more time on your hands and want to circle the entire island then the 4 hour cruise is for you.
NY-Brooklyn Bridge and Manhattan Bridge from the Circle Line