Navin Johnson, 'The Jerk' (1979)
Ignorance is bliss; therefore, Navin Johnson must be the most ecstatic guy in the world. Unable to fathom his own Caucasian exterior, the lead idiot in Steve Martin's classic comedy tends to resort to spastic faux-karate when encountering America's deep-seeded racism. There's no one he can't hear out, including his dog (who feeds him false information about a motel fire, because Navin can definitely speak dog). Yes, he causes more property damage than Superman in Man of Steel and is so untouched by the horrors of reality that he's convinced a sniper trying to put one in his brain is really an aluminum can-related phenomenon. Without being that dumb, however, would Navin have Invented the Opti-Grab or wooed a woman named Marie (Bernadette Peters) with his rendition of "Tonight You Belong to Me"? Never mind the film's title: He's the best kind of stupid.
Dumb Factor: 6