The Marvel film, starring Michael Fassbender and James McAvoy and featuring split-second cameos from original X-Men Hugh Jackman and Rebecca Romijn, toppled The Hangover Part II, which dropped a spot to two with a second-weekend haul of $32.4 million (£20.3 million).
The comedy has taken in $190 million (£119 million) in just 10 days in the U.S.
Kung Fu Panda 2 and Pirates of the Caribbean: On Stranger Tides round out the new top four.
Severe weather struck America's southern states, including Texas, Oklahoma and Kansas, earlier this week (beg23May11) - just days after a powerful twister claimed more than 120 lives and devastated whole neighbourhoods in Joplin, Missouri.
Munn, who was born in Oklahoma, has been watching the tragedy unfold on the news and on Thursday (26May11) took to her Twitter.com page to urge fans to help locate Ryan Hamil, a three-year-old boy who went missing during the storms.
The Date Night star was left devastated after learning the youngster and his 15-month-old brother Cole both died in the disaster.
In a series of posts on Twitter, Munn writes, "My thoughts/prayers with tornado victims. My heart goes out to the Hamil family in Oklahoma.. Their 2 little boys didn't survive the tornado. So sad. My hope & lots of good thoughts & wishes are w/the (with the) people affected by the tornadoes.... Big hug."
"What I'd seen on the television was unlike anything that I could describe once I got down there. I just wanted to do something." Charlie Sheen on his Torpedoes For Tornadoes campaign to raise cash for those struggling in the wake of the recent storms in America's southern states. The actor has teamed up with Snoop Dogg and Filter star Rob Patterson to record a charity single, Winning, which is available to download via iTunes.com.
The actor has collaborated with rapper Snoop Dogg and former Korn guitarist Rob Patterson to create the song, named after his famous catchphrase.
The track will be made available to download from Tuesday (10May11) and Sheen has promised to give the proceeds to victims of the massive storms which swept across six southern U.S. states late last month (Apr11), leaving almost 300 people dead.
In a post on his Twitter.com page on Sunday (08May11), Patterson wrote, "2 days til the single Winning from me, Snoop & Charlie comes out on iTunes! Donating proceeds to the tornado victims."
But Patterson, who also helped Sheen create the music for his live tour, has urged fans and critics to enjoy the track for what it is - pure entertainment.
He tells the Los Angeles Times, "Look, it's a good song. But I honestly don't want people to take it seriously. It's meant to be fun and entertaining... The song started off being about Charlie Sheen. But when Snoop came in, I said I didn't want it to be just about Charlie and repeating his key phrases. It's unilaterally about winning."
Meanwhile, Sheen has lavished praise on his rap pal for his professionalism during the recording of the song.
He says, "(I had) a shortlist of people who would be able to carry the 'winning' wildfire the best. Snoop was on top of that list... Snoop is a warlock. He came in and nailed it in a couple of hours."
Sheen has already launched a website urging fans to donate cash for those affected by the tornado disaster and promises an autographed baseball for those who pledge at least $100 (£62.50) to the cause.
Storms swept across six southern states last month (Apr11), and the worst damage occurred in Alabama, where more than 200 people died.
Cosby visited Birmingham's Miles College on Sunday to speak to graduates and he encouraged them to come together to help rebuild communities.
He said, "Think about what is needed in your neighbourhoods and go about your entrepreneurial self. Work it, rebuild it. This is Alabama. This is you."
The former Two and a Half Men star visited the ravaged state of Alabama on Sunday (01May11) after almost 300 people were killed when devastating storms hit the south of the country last week (beg25Apr11).
He promised to use his current high profile to help raise money for those affected by the disaster - and now he's launched a website urging fans to donate to the cause.
The site - called Torpedos Against Tornados in honour of Sheen's recent My Violent Torpedo Of Truth/Death Is Not An Option stand-up tour - gives fans the chance to donate cash via PayPal, with the promise of a special gift for big contributors.
Sheen is pictured on the website homepage next to the message: "Donate at least $100 and get a baseball personally signed by Charlie Sheen!"
Severe storms swept across America over a 24-hour period, beginning on Wednesday (27Apr11), levelling entire neighbourhoods and claiming nearly 300 lives.
The former Two and a Half Men star, who toured the damaged southern state on Sunday (01May11), vowed to help people by organising a benefit, reports the Associated Press.
He says, "I want (to bring) some money, hope, faith and healing to the area."
The actor decided to visit the city of Tuscaloosa after a University of Alabama student reached out to the star via Twitter.com, begging him to perform a relief show to raise funds for the devastated people.
In a response to the request, Sheen wrote, "Alabama; Heading your way. On a recon mission. My Cadre right behind me. You need help. I'm bringing it. DogSpeed."
A date for the event has not yet been announced.
The actor has been raising quite a bit of cash for good causes during tour stops on his one-man My Violent Torpedo Of Truth/Death Is Not An Option trek across North America - Sheen cut a cheque to the Organization for Bipolar Disorder Awareness in Canada last month (Apr11) and also helped raise funds for disaster relief in Japan. On Saturday (30Apr11) he raised $20,000 (£12,500) for the family of brain damaged baseball fan Bryan Stow at a show in San Francisco, California.
Severe storms swept across six southern states over a 24-hour period, beginning on Wednesday (27Apr11), devastating entire neighbourhoods and claiming nearly 300 lives.
Executives at America's Fox network had planned to air three crossover episodes of MacFarlane's popular shows on Sunday (01May11), but the TV special has been postponed because of its storm storyline.
A statement from Fox reads, "In light of the recent storms that have affected the nation, Fox has decided to postpone the crossover episodes that were originally scheduled to air this Sunday."
An independent film festival in Durham, North Carolina was affected by blackouts during the devastating storms which spread across America's south at the weekend (16-17Apr11). The Full Frame Documentary Film Festival continued despite the power cuts, with some movie insiders hosting presentations in the dark.
"Thank you to... my wonderful wife, who is my mast through the storms of life." CHRISTIAN BALE gets emotional as he pays tribute to his wife Sibi after being named Best Supporting Actor at the 2011 Academy Awards for his role in THE FIGHTER.