Jackson says he's been a comic fan his whole life, but some of the biggest cheers came for the man who created "The Avengers" universe, Stan Lee.
"It's just that I happen to have this quality: I'm adorable!" said Lee. "I still feel like a kid, you know? When I'm with these teenagers and these young people, I'm never happier."
The young people who make up the Avengers include Robert Downey, Jr., as Iron Man, Chris Evans as Captain America, Jeremy Renner as Hawkeye, Chris Hemsworth as Thor and Scarlett Johansson as the Black Widow.
"Being able to play a woman who is, you know, not a love interest, she's not a wife, she's not a sidekick, she's her own, you know, she's a mercenary, really. It's a rare opportunity, I think," Johansson said.
Mark Ruffalo also makes his first superhero appearance as the Incredible Hulk.
"I didn't know what to expect, I've never done anything like this before, there's been a lot of, you know, talk about 'Is it going to be any good? Can Mark Ruffalo do it?' and to see it kind of coming to life we kind of intended it to is very satisfying," said Ruffalo.
The film features plenty of action, special effects and humor!
"Even if I have a really small part in a movie, somehow I end up in the trailer," said Clark Gregg of his character, Agent Colson. "It's because of my four fans. They just want my four fans in the theatre."
"The Avengers" hits theaters on May 4.