Iron Man is one of the most popular Marvel superheroes, and that is largely due to his portrayal in the MCU. As part of one of the most successful movie franchises in the last decade, Robert Downey Jr. played the reformed arms dealer in a way that made him sympathetic to the audience and had enough charm to win over even the franchises' biggest detractors. Therefore, the character of Tony Stark/Iron Man received his own movie trilogy and was included as a big part of The Avengers series.