Nickelodeon's 20th Kids Choice Awards feature host Justin Timberlake. The green-slime-filled awards show airs live at 7 tonight on Sunflower Broadband Channel 76.

Los Angeles ? Forget who won this year’s Oscars, Grammys and Emmys, there are millions of movie, music and TV fans out there just dying to learn which celebrity burps the loudest.

And they will find out, as well as learn the winners in more than a dozen other categories for film, TV, music, sports, books and video games during tonight’s 20th annual Kids Choice Awards.

The event, long the loudest, messiest and at times the grossest of Hollywood’s many award shows, has grown into one of the entertainment industry’s most popular as well. It has become a hit not only with the 14-and-under set, but with the celebrities who now attend in droves.

The show will be broadcast in the U.S., Europe, Russia, Israel, Asia, Australia and Latin America.

“It’s just one of those things that’s fun to show up at,” said Justin Timberlake, the defending burping champion and host of this year’s show. “Hey, any awards show you can wear jeans and a T-shirt to is kind of cool.”

Jeans and a T-shirt is almost required dress for those honored with an award at this show, as at any moment any of them could be drenched in green, gooey slime, another hallmark of the show. Timberlake himself was sprayed with the stuff in 2001 when he was with his former band ‘N Sync.

X Games champion Tony Hawk once skateboarded into a vat of green slime from a platform several stories high. BMX bike champion Mat Hoffman parachuted out of a plane, while on his bicycle, straight into a vat of green goo. Last year, Robin Williams was sprayed with it.

“He seemed to revel in it,” says Cyma Zarghami, president of Nickelodeon Television, who has been involved in all 20 Kids Choice Awards. She can recall the show’s early days, when it was a struggle just to get a nominee to show up.

“It was a sad day back then, trying to get somebody to accept an award from us,” Zarghami recalled with a laugh. “It took a long time to get them to come.”

That began to change 10 years ago, and now this year’s list of celebrity nominees who are expected to attend includes Will Smith, Halle Berry, Julia Roberts, Queen Latifah and Johnny Depp, who was a sliming victim two years ago. Musical performers include Gwen Stefani and Maroon 5.

“I think it reflects the growing importance of the family audience,” Valerie Van Gelder, president of marketing for Columbia Pictures, said of the program’s growth in popularity.

Williams’ sliming last year, she added, helped get attention for his movie “RV.”

“Kids have an enormous amount of influence over their entertainment choices these days and they’re very opinionated, so we’d like to try and make sure they know about the projects that are geared to them,” she said.

The show is done before an audience of 10,000 or so shrieking kids lucky enough to score tickets to it.

“I don’t think there’s anything quite like walking down the orange carpet with kids screaming the entire time,” Zarghami said. “And I think they get it. The minute the celebrities step on the orange carpet they realize it ain’t the Oscars.”

Then there is the fun factor, said Timberlake, adding, “You put me in front of a bunch of kids and I become a circus clown.'”

He has won four Grammys, but he preferred to talk about a more endearing prize.

“The only award that means more than the world to me is the prestigious burp award,” Timberlake joked. “I don’t think there is a higher honor at the Kids Choice Awards, and I’m pretty proud that I’m the big burp champion of all time.”

Indeed, he is the only person to win the award twice.