'Mrs. Doubtfire' (1993)
Who wasn't charmed by this 1993 film? Williams was brilliant in his portrayal as Daniel Hillard, who disguises himself as an elderly female housekeeper -- Mrs. Doubtfire -- to get closer to his children after a bitter divorce. The original film was so popular that there were talks to make a sequel, though sadly, the film's status is now questionable given Williams' death.