Even if you have no business to go to Roosevelt Island I would highly recommend this attraction. Where else can you take a commuter tram ride? You feel like youre in Switzerland and get a great view of the East River and Manhattan. They still use tokens here and the one way trip will run you $2. So you could save 50 cents if you have some old tokens floating around. Take a walk around Roosevelt Island. Its a VERY weird place. There is a Roosevelt Island bus which will take you all over the island for 25 cents.
Pros: View, Unique