It Happened One Night (1934)

Directed by Frank Capra

Frank Capra practically invented the now well worn romantic comedy formula with this movie.  A man and woman can't stand each other but are stuck together due to circumstantial reasons and end up falling in love.  But honestly that doesn't do this film justice because it is a very funny charming movie.  The famous scene is one where they are on the road trying to hitch a ride.  Clark Gable is trying to man'splain ride hailing technique when Claudette Colbert gives him a lesson in the power feminine allure.