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.
Dumbo, which stands for 'Down Under the Manhattan Bridge Overpass,' is a neat neighborhood in Brooklyn that is at an awesome vantage point of Manhattan. There are cool rocks on the shore of Brooklyn Bridge Park that are fun to relax on and sneak alcoholic beverages.
If you're far up in Greenpoint and need caffeine + snack, Bakeri is my spot (I say "bake-ery", others say "bach-ery"—I still vote the former). Known for their baked goods—both savory and sweet—it's the perfect spot for a coffee meeting, small breakfast, or a solo book read. There's one large communal table in the center, plus a few two-tops and decent counter space—one of the rare cafes with enough room that it's rarely packed (except saturday!).