If towering 1,353 feet above the ground in a clear box is your idea of a rush, you'll have to wait your turn to soar. Formerly known as the Sears Tower, the Willis Tower Skydeck is a top attraction for visitors to the Windy City, which means lines to the top can be grueling. Regular admission costs about $15.95, and a fast pass (quick access to the elevators) runs about $30, but remember there is very little room at the top.
(Photo: Ryan-o via Flickr. CC Attribution. http://www.flickr.com/photos/roper/)