5. Rainier Wolfcastle/McBain
The Simpsons' long-running action-hero Ah-nold parody, Rainier Wolfcastle and his box-office–breaking McBain character allowed Shearer to exercise a "cool, dry wit" and fearless short fuse that his other characters lack. Yet another example of the actor's malleability, Wolfcastle speaks in a heavy Austrian accent, which sometimes becomes exasperated when he has to play his signature action hero in any number of movies (best title: McBain VI: You Have the Right to Remain Dead) and scream a villain's name – like, "Men-doh-zaaaaaa!!" The McBain character is so over-the-top and memorable that one Simpsons superfan stitched together a full McBain movie on YouTube.