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.
Erie Basin is a really wonderful little shop full of old, creepy and beautiful things, such as Victorian mourning jewelry (some with hair in it), Freemason masks from the 1900's, tiny children's rings from the 1700's, and all kinds of other treasures. It is really as much a museum as it is a store, and all of the items have a haunting and unique aura.
If you are in need of a moment of solitude, this is the place. On my first visit I was in awe of how time seemed to stand still inside. It has now become a sanctuary from the city when I need the pace of life to slow down.