My Fair Lady (1964)

Gloriously witty adaptation of the Broadway musical about Professor Henry Higgins, who takes a bet from Colonel Pickering that he can transform unrefined, dirty Cockney flower girl Eliza Doolittle into a lady, and fool everyone into thinking she really is one, too! He does, and thus young aristocrat Freddy Eynsford-Hill falls madly in love with her. But when Higgins takes all the credit and forgets to acknowledge her efforts, Eliza angrily leaves him for Freddy, and suddenly Higgins realizes he's grown accustomed to her face and can't really live without it.