Broken O Ranch, Augusta, Mont. – between $90 million and $132.5 million

Kensington Palace Gardens, London, U.K. - £117 million

Kensington Palace Gardens, London, U.K. - £57 million as of 2004

Ellison Estate, Woodside, Calif. - $200 million

Fleur de Lys, Holmby Hills, Calif. - $102 million

Villa Leopolda, Villefranche-sur-mer, France - $750 million as of 2008