Much of the success of the 'Iron Man' films can be attributed to Robert Downey Jr.'s portrayal of the billionaire, weapon-making jerk. It's quite possibly one of the greatest casting choices in movie history. Here are eight things you probably didn't know about Robert Downey Jr. and his portrayal of the man in the iron mask.

This time around, Iron Man faces off against his sickest opponent yet, the sinister Mandarin who's hell bent on destroying the world and Tony Stark in the process.

'Iron Man 3' can't come soon enough.