28. HUMPHREY BOGART
The Treasure of the Sierra Madre (1948)

Cowardly, untrustworthy, and burdened with a suspicious nature that flares to full-blown paranoia, Bogart plays south-of-the-border bum Dobbs perfectly, with eyes like a scared rabbit's and a black beard occasionally encircling his mouth, making him look like a dumb, down-and-out clown. Critics took notice, but the star's Oscar payoff came with a less risky, comic variation on Dobbs in 1951's African Queen.