Some very good calls here. Sorry to be a puritanical killjoy, but I think some of you are just confusing pretty with sexy (or even, more bluntly, visual Viagra).
Ingrid Bergman – sublimely beautiful, never found her remotely sexy in anything I saw her in.
Charlotte Rampling in her prime (mid sixties to mid seventies) — not classically pretty, perhaps the sexiest woman walking the earth earth for the fifteen-year-old that I then was. Still decidedly sexy (and visual Viagra) well into her fifties.
But I trawled through this whole thread so as not to post the one I thought would have already come up several times. Bo Derek in 10. She is … 10. Nothing much to the film, but her… by gum!
Special shout out for the women posting on this thread: not easy for me to see that men are good looking, but even I can see that Jude Law in The Talented Mr Ripley is just ridiculously handsome. Also, Paul Newman in films like Cool Hand Luke and Butch Cassidy and the Sundance Kid.