Ever watched 'Soft beds and Hard battles' ?

Mike Myers plays several roles in the Austin Powers films. In some of the episodes, he plays as many as 4 characters. Of course there was the "Rich Little Christmas Carol" where Rich Little plays almost everyone in the story, but he is not disguised as meticulously each time as other actors have been in multiple roles.

Eddie Murphy is well known for playing multiple characters in his movies. I think he played a few different characters in "Coming to America", "The Nutty Professor", and "Norbit".