4. Kirk Lazarus - Tropic Thunder (2008)
I'm not sure how appropriate Robert Downey's Jr. zany turn in Ben Stiller's war movie spoof
Tropic Thunder is exactly, but I can't help but think that it's one of the most insanely demented and ultimately brilliant performances ever put on the big screen. And going by the hive mind, I think it's safe to say that the rest of the world firmly agrees with that - perhaps because we're still as stunned to see the transformation today as we were back in 2008. As Kirk Lazarus, a hilariously acute blend of actors like Russell Crowe and method types like Heath Ledger, Downey Jr. perfectly encapsulates the Oscar-baiting tendencies of some of Hollywood's most "dedicated" - within the confines of the movie, Lazarus undergoes a risky new procedure to dye his skin black in order to play Sgt. Lincoln Osiris, a Vietnam War in the movie's movie-within-a-movie "Tropic Thunder." The results, as you'll see below, were consistently hilarious. Risky as this was for an actor of Downey Jr.'s credibility, his performance was hailed by audiences and critics alike: in fact, it's probably the most interesting thing about the entire movie, which, perhaps, felt a little restricted by its one-note premise. Somewhat ironically, Downey Jr. garnered an Oscar nomination for this role in the Best Supporting Actor category. If that notion doesn't strike you as totally insane, I really don't know what will.