Tiffany & Co.Regal Pear Shape Diamond Pendant set in platinum$2.5 million

(£700,000, €1.1 million, 57.3 million rupees, C$1.5 million, A$1.8 million)
Macho Guy Equivalent: Prewar Classic Six Co-op on Park Avenue in Manhattan
Showstopper or credit-limit topper? Either way, Tiffany's Majestic Diamond Necklace will be center stage wherever it's displayed. With a fluid design that lies softly on the neck--and really, what other way is there?--this glittering choker evokes breathtaking glamour, with a 41.4-carat, pear-shaped diamond accompanied by a multitude of round and pear-shaped diamonds. Each stone is top-of-the-crust in color and clarity, of course, as is the pretty blue box it comes in.