John Travolta [1] may be best known for his role as the disco-dancing Tony Manero in Saturday Night Fever, but before that, he was Vincent "Vinnie" Barbarino, the cocky leader of the James Buchanan High School Sweathogs on the ABC comedy Welcome Back, Kotter. Travolta went on to star in memorable films like Grease, Pulp Fiction, and Get Shorty — oh, and let's not forget Look Who's Talking!