Cary Grant should have played Jeff!

Hitchcock used both actors, Stewart for "everyman" roles and Grant for glamour roles... but the thing is, Jeff is stealth glamour role! Jeff is a man of action, an international man of mystery temporarily inconvenienced by a broken leg, and someone who's supposed to be appealing to the hottest women, and we don't get ANY of that from Stewart. I mean Stewart is a very good actor, but he was 45, out of shape, going gray, and was never believable as an international man of action on his best day.

But we would have bought Grant as the sexy man of action right off the bat, even if he was in a wheelchair! Sure, Grant was actually a little older than Stewart, but he was athletic, energetic, and muscular, he would have brought a sense of frustrated energy to the role that Stewart entirely lacks. Stewart seems old before his time in this movie, and of no interest to the likes of Grace Kelly, but Grant? Still sexy, even with a cast on his leg!