The Frank Stella’s are the best. They are all over the city and they always look amazing. Two of my favorites are the Saatchi and Saatchi lobby (pictured) and the Citi Corp building in Midtown.
The best way to enjoy Manhattan is from Brooklyn. Transmitter Park offers views without the crowds, and you can pick up coffee-to-go and treats from nearby Ovenly. The India St/Greenpoint Ferry is a 5 minute walk and will take you all the way to the Rockaways in the Summertime.