One of my favorite scenes in North by Northwest takes place on the train, with some of the best Hitchcock sexual innuendo ever. Take this exchange between the dashing, if greying, Cary Grant and the tiny-as-a-bird Eva Marie Saint as they gaze lustfully into each other's eyes at close range:
Eva: I'm a big girl.
Cary: Yeah...and in all the right places too.
For 1959 this was downright tawdry, and the 3 minute long foreplay session was pretty daring. But the most hilarious innuendo is in the film's final shot. Watch this and try not to giggle.