"Iron Man 3" took off with the second-biggest U.S. opening weekend ever, pulling in an estimated $175.3 million in ticket sales. Check out the 20 movies that have made the biggest splashes on their opening weekends, according to Box Office Mojo.
20. "Star Wars: Episode III - Revenge of the Sith." Release date: 2005. Domestic gross on opening weekend: $108.4 million.