Actor who stripped down: Sharon Stone
Why they're fully nude: Sex = power.
The female form is at its most powerful in the hands (and legs) of Sharon Stone, who ruled the 1990s with an icy sexuality and carefree attitude about showing off what her mama gave her. Even with two full frontal sex scenes, it was Basic Instinct's half frontal scene—where a commando Stone strategically uncrosses and crosses her legs to the nervous delight of Wayne "Newman!" Knight—that became the film's most iconic moment.
The film, directed by Paul Verhoeven from a script by Joe Eszterhas, became one of the year's biggest hits. And shot Stone to the top of Hollywood's A-list. (Though by the time she reprised her role as full frontal goddess Catherine Tramell in the 2006 sequel, both the actress and her nether regions had fallen a bit off the radar.)