25/28
Theo Wargo/WireImage
2003
Gladiator goddess or sci-fi dream? Either way, this vivacious look goes down as one of her best.
26/28
Dimitrios Kambouris/WireImage
2002
The former Victoria's Secret model was red hot, as she channeled the iconic Betty Boop.
27/28
Theo Wargo/WireImage
2001
In her second year hosting, the star went full Lady Godiva—horse and all!
28/28
DMIPhoto/FilmMagic
2000
While the model's looks have become a lot more elaborate, for her very first party she was just Heidi (as in the character from Johanna Spyri’s German novels), choosing to dress up in a dirndl "but not a tradtional dirndl," she told People. "And in those days I still did my hair and makeup by myself."