Owning a yacht is the ultimate status symbol. Universally perceived as the exclusive domain of the rich and the famous, yachting is a decidedly rarified world. Arguably the most well-known private yacht of all time, the 325-foot (99-meter) Christina O, owned by Aristotle Onassis in the 1950s and 60s, was the playground for heads of state such as Winston Churchill and the Kennedys, opera diva Maria Callas, and Hollywood sweethearts such as Ava Gardner and Elizabeth Taylor. Pictured here along with the newly rebuilt Christina O are 20 other mega-yachts, including the newly completed and wildly colorful Guilty, designed by Jeff Koons for the art collector Dakis Joannou; Tom Perkins' modern sailing yacht Maltese Falcon, the ultramodern sailing yacht Esense, and the refit classic Delphine. The yachts pictured here are special for many reasons: because they are the fastest, or the most innovative, or the most technologically advanced, or because of their travels to exotic locations around th