The program is an annual stop for Hollywood stars who are popular among teenage and young viewers watching the Nickelodeon cable TV network, and this 25th anniversary was no exception.
Hosted by "Men in Black" movie star Will Smith, the awards featured performances by Katy Perry and British boy band One Direction, who performed their hit "What Makes You Beautiful" from the album "Up All Night."
But as always, the green slime was the biggest star at the show where Bieber won favorite male singer in fan voting.
On stage, Bieber took the orange blimp trophy from Smith, then the show's host had a surprise for the 18-year-old pop star. Bieber was also voted by fans as the celebrity they most wanted to see get slimed, and the green goo flowed from the rafters and water cannons aimed at the stage.
There was so much goo splashing around in the finale that it splattered on the face of a surprised first lady.
Obama was on hand at the popular show to give the "big help" blimp trophy to country star Swift.
The honor, bestowed on Obama two years earlier for her work with kids fitness and health, goes to a celebrity who has devoted time and energy to charitable causes. Swift was singled out for her work to stop bullying and for providing aid to tornado victims in the southern United States.
Swift "rocketed to the top of the music industry, but still keeps her feet on the ground," Obama said about the 22-year-old country singer, calling her "someone who is going to keep making sparks fly for all of us in the years ahead."
Other winners included made-for-TV band Big Time Rush, named favorite music group.
Selena Gomez, 19, was named favorite female singer for her work with pop band The Scene, as well as favorite TV actress in the "Wizards of Waverly Place," which ended its run on the Disney Channel earlier this year.
"Twilight" stars Kristen Stewart and Taylor Lautner both grabbed orange blimps. Stewart, 21, was named favorite movie actress. Lautner, 20, earned the title best "butt kicker" for his role as werewolf Jacob Black in the vampire romance flicks.
Favorite movie actor was Adam Sandler, 45, known for goofy comedies such as his recent "Jack and Jill."
Nickelodeon's "Victorious" was named top TV show.
(Reporting By Bob Tourtellotte; Editing by Will Dunham)