5. International Finance Centre, HongKong

A prominent landmark on Hong Kong Island, it consists of two skyscrapers, the ifc mall, and the 55-storey Four Seasons Hotel Hong Kong. Tower 2 is the tallest building in Hong Kong, usurping the place once occupied by Central Plaza. It is the third-tallest building in the Greater China region and the seventh-tallest office building in the world, based on structural heights; by roof height, only the Taipei 101, Shanghai World Financial Center, and Sears Tower exceed it. It is the exact height of the former World Trade Center. The International Commerce Centre, currently under construction above the MTR Kowloon station and scheduled for completion in 2010, will usurp 2IFC's various titles.

4. Jin Mao Tower

The Jin Mao Tower is an 88-story landmark supertall skyscraper in the Lujiazui area of the Pudong district of Shanghai, People's Republic of China. It contains offices and the Shanghai Grand Hyatt hotel. Until 2007 it was the tallest building in the PRC, the fifth tallest in the world by roof height and the seventh tallest by pinnacle height. Along with the Oriental Pearl Tower, it is a centerpiece of the Pudong skyline. Its height was surpassed on September 14, 2007 by the Shanghai World Financial Center.

3. Sears Tower

The Sears Tower, a skyscraper in Chicago, Illinois, has been the tallest building in North America since 1973. It surpassed the World Trade Center, which itself had surpassed the Empire State Building only a year earlier. Commissioned by Sears, Roebuck and Company, it was designed by chief architect Bruce Graham and structural engineer Fazlur Khan of Skidmore, Owings and Merrill.

2. Petronas Twin Towers

The Petronas Twin Towers (also known as the Petronas Towers or Twin Towers), in Kuala Lumpur, Malaysia were the world's tallest buildings, before being surpassed by the Taipei 101. However, the towers are still the tallest twin buildings and office building in the world. Tower 1 was built by Hazama Corporation and Tower 2 by Samsung Engineering & Construction and Kukdong Engineering & Construction (both of South Korea). They were the world's tallest buildings from 1998 to 2004 if measured from the level of the main entrance to the structural top, the original height reference used by the US-based Council on Tall Buildings and Urban Habitat from 1969.

1. Taipei 101

Taipei 101 is a 101-floor landmark skyscraper located in Xinyi District, Taipei, Taiwan. The building, designed by C.Y. Lee & partners and constructed primarily by KTRT Joint Venture and Samsung Engineering & Construction, is the world's tallest completed skyscraper according to the CTBUH, the arbiter of tall building height. Taipei 101 received the Emporis Skyscraper Award in 2004. It has been hailed as one of the Seven New Wonders of the World and Seven Wonders of Engineering (Discovery Channel, 2005).