6. 666 Fifth Avenue $1.8 Billion

Lobby of 666 Fifth Avenue with art by Isamu Noguchi

In 2007, 666 Fifth Avenue was the most expensive ever paid for a single office building in the United States. Kushner Properties was the buyer, a family-owned real estate company, and this was one of its first major forays into the Manhattan real estate market. The New York Times wrote that the purchase was “considered a classic example of reckless underwriting,” reflecting the height of real estate transactions just before the last recession, but also notes the clever restructuring and deals that have taken place since then to keep the building in play. Today, most know this building because of the the Uniqlo store on the ground floors, designed by architect Masamichi Katayama and his firm Wonderwall. It is also home to the Hollister store, Zara and Tissot. Inside, there is an Isamu Noguchi installation in the lobby.