Squeezed into a fluorescent green superhero suit, Jack Black opened Nickelodeon's 21st Annual Kids' Choice Awards by singing a wacky ode to the wonders of slime, playing the bongos and finishing off with a swift karate chop that demolished a stack of cinder blocks.

"Welcome to the slimiest, starriest, 'choiciest' awards show -- ever!" Black yelled to an auditorium filled with screaming children.

Yes, welcome to the kiddie Oscars, where Nickelodeon viewers vote for their favorite winners and the Slime Meter tallies the madness of the evening. This year, in fact, 88 million votes were clocked on the Nickelodeon website, Black announced.

Jessica Alba won favorite movie actress, the first prize of the evening. She accepted her blimp trophy from Janet Jackson and actor Josh Bell.

"I love Nickelodeon! I wore green today in honor of the slime," Alba said. "I love making movies for you all."

The Jonas Brothers won the Kids' Choice for favorite music group. The three brother act from New Jersey arrived on stage in pastel suits and accepted the award from "Ugly Betty" actress America Ferrera and Emile Hirsch, who stars in the upcoming Warner Brothers movie "Speed Racer."

Surprise box office champ Miley Cyrus, star of the 3-D film "Hannah Montana/Miley Cyrus: Best of Both Worlds Concert Tour," picked up favorite female singer. (Guests James Marsden and Hayden Panettiere pulled the winning envelope from beneath a dirty, gooey toenail on a giant foot.)

Tabloid-friendly couple Ashlee Simpson and Pete Wentz joked about sharing eyeliner before revealing "American Idol" won the favorite reality show. The award was collected by "Idol" host Ryan Seacrest.

Chris Brown, singer of the hit "Kiss Kiss" (featuring T-Pain), collected favorite male singer and thanked his label Jive Records, his mom and "all the ladies."

"Punk'd" creator Ashton Kutcher, dressed in a snazzy tuxedo, presented Nickelodeon's Wannabe Award. Akin to the Academy Awards' Jean Hersholt Humanitarian Award, the Wannabe is given each year to the best celebrity role model or inspiration.

This year the honor went to actress Cameron Diaz. She asked the kids in the audience to whisper, and then scream, "We are the future! And the future is bright!"

After an announcer encouraged viewers to "burp the belch fantastic," Will Smith, with his children Jaden and Willow, introduced a musical performance by Cyrus who sang "G.N.O. - Girl's Night Out."

Pop artist Rihanna, and elastic actor Brendan Fraser, who stars in New Line's upcoming "Journey to the Center of the Earth" 3-D, presented a double win to the Nickelodeon series "Josh and Drake," which picked up favorite TV show and favorite TV actor. That award went to series star Josh Bell.

"The Office" star Steve Carell and "Saturday Night Live's" Weekend Update co-host Amy Poehler opened the envelope for favorite movie. The animated hit "Alvin and the Chipmunks" beat out "The Transformers," "Are We Done Yet?" and "The Pirates of the Caribbean: At World's End."

Providing a brief interlude between award presentations was "Project Runway" host Heidi Klum. The fashion personality donned a "slime butt belt" and soared through the air aiming her backside at an enormous target covered with slime balloons.

"There goes one brave supermodel!" Black enthused.

For a complete list of 21st Annual Nickelodeon Kids' Choice Awards winners visit HERE.