3. Danny DeVito As Herb Powell In "Oh Brother, Where Art Thou?" And "Brother, Can You Spare Two Dimes?"
After a near-death experience, Grampa admits to Homer that he fathered a child out of wedlock -- and so Homer has an older brother. Homer eventually finds his brother, Herb Powell, and the entire family visits him in Detroit. Powell, it turns out, is a millionaire, his fortune made in the auto industry. He shows great kindness and generosity to his new family, but when Homer's prototype for a car ends up bankrupting him, Powell disowns his newly-found brother. That wasn't the end of "Unky Herb's" story, though -- he would return the following season, homeless and desperate, but with an idea. Borrowing $2000 from Homer, he was able to create a prototype for something every parent could use -- a baby translator (in DeVito's voice, naturally). Like that, Herb was rich again. Herb was voiced by Danny DeVito, and although DeVito's made a career out of playing sleazeballs - from Louie DePalma to Frank Reynolds -- his gravely voice only makes Herb more endearing, giving him a "from the streets" feel and establishing him as a common man made good. His anger at Homer -- and his eventual forgiveness of his brother -- are both palpable and moving.
Best line: "I want what the dog's eating."