"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.
3. "Harry Potter and the Deathly Hallows Part 2." Release date: 2011. Domestic gross on opening weekend: $169.2 million.