After the monumental success of Iron Man Downey simply could have coasted off the success of that franchise and waited for the Oscar bait to come. What no one expected following the comic book success was Downey donning black-face and turning in one of the best comedic performances of the decade. He was justly rewarded with an Academy Award nomination, unfortunately he was going up against Heath Ledger for The Dark Knight.
Regardless of who went home with the trophy Oscar night Downey solidified his status as an actor unafraid to seek roles outside the norm. What's most remarkable about the portrayal is that at no point during the film did the concept seem offensive at all. Lazarus's borderline obsessive devotion to his craft is sent up so well we forget that it's Iron Man, Charlie Chaplin and countless others under that make-up. At that point the only Thunder in the film belonged to Downey.