"What's the opposite of humbled? We're Biebered to be standing here," said "Avengers" writer-director Joss Whedon as he accepted the top prize Sunday. "This is the award that means the most to me. I am so grateful and very excited for 2015; we're going to bring you 'Avengers 2.'"
"The Avengers" also won best fight and best villain for actor Tom Hiddleston.
"Silver Linings Playbook" won best performance for stars Bradley Cooper and Jennifer Lawrence and best kiss for the on-screen smooch they share. Cooper accepted his award and the kiss prize. Lawrence was not at Sunday's ceremony.
Wilson, who opened and closed the show wearing Iron Man-style armor, won breakthrough performance for her work in "Pitch Perfect" and shared in the film's award for best musical moment. Its stars, including Brittany Snow and Skylar Astin, opened the show with a mash-up medley.
Other musical acts were Macklemore & Ryan Lewis and Selena Gomez, who debuted her new song, "Come and Get It," with a Bollywood-inspired performance.
The MTV Movie Awards are as much about the anticipated movies of the upcoming summer season as they are about the finest films of last year. Fans vote online for the winners in traditional and irreverent categories such as best fight, best kiss and best shirtless performance.
"Twilight" heartthrob Taylor Lautner won the shirtless award.
The show also included new footage from next month's "Iron Man 3" and the world premiere of "The Hunger Games: Catching Fire" trailer, introduced by one of its stars, Liam Hemsworth.
Stars from other summer films— including Chris Pine, Zoe Saldana and Zachary Quinto from the "Star Trek" sequel and Vin Diesel and Michelle Rodriguez from the "Fast & Furious" franchise — appeared as presenters during the ceremony.
Other presenters included Brad Pitt, Chris Rock, Adam Sandler, Seth Rogen, Zac Efron, Snoop Dogg/Lion and Kim Kardashian.
Hollywood has increasingly used the fan-driven MTV Movie Awards as a platform to promote its summer product. This year, the show was moved up from June to April to incorporate the entire blockbuster season, which begins in early May.
Honorees and presenters represent upcoming movies, and the ceremony is typically peppered with commercials for forthcoming films and DVD releases.
Emma Watson, a star of this summer's "The Bling Ring," received the Trailblazer Award.
Will Ferrell wore a three-piece suit covered in dollar bills to accept the Comedic Genius Award from "Game of Thrones" star Peter Dinklage.
"For those of you sitting here tonight who don't think I'm funny, I'll be happy to fight you in the parking lot after the show," said Ferrell, who is currently at work on "Anchorman 2," slated for release later this year.
Jamie Foxx was a double winner, too. He shared the best WTF moment award with Samuel L. Jackson for their scenes together in "Django Unchained," and later thanked his daughter, parents and siblings in the audience as he accepted the Generation Award for his career in film.
Foxx stars in June's "White House Down."