5. The Blues Brothers (1980)
Shortly after leaving Saturday Night Live in 1979, John Belushi and Dan Aykroyd were at the top of their game. They had both appeared in a Steven Spielberg film, Belushi had been in Animal House, and they were in great demand due to their SNL popularity. They cemented this status with 1980's The Blues Brothers, which featured Belushi and Aykroyd as Jake and Elwood Blues, respectively. The story begins with Jake being released from jail, at which point he learns the church where he and his brother were raised is about to be demolished. In an effort to save it, they reform their band and set out on "a mission from God". Not only was the film a comedy hit, it gained considerable praise for the cast and their performances. Some were professional musicians (Aretha Franklin, Ray Charles, James Brown) while Belushi and Aykroyd were just actors who happened to be really really good at singing and playing music.