The hottest up-and-coming Hollywood stars hit up the Teen Choice Awards Sunday night. And "Extra" got the scoop on all the action, including who threw the biggest hissy fit of the year and who had the most serious lip lock as stars like Usher, Jessica Alba and Halle Berry let their hair down and came face to face with their most loyal fans.

"Simple Life" co-stars Paris Hilton and Nicole Richie hosted the big event, and only we were allowed backstage before the show. And although, Paris admitted to us, "I'm just afraid I'm going to mess up my lines," the hotel heiress did just fine at show time. But you can't blame the notorious party girl for her butterflies. Ten days ago, photographers shot her battered and bruised at the Los Angeles airport, and last week her apartment was burglarized.

"They took jewels and they took money, everything," Hilton revealed.

So how did Paris pull it all together? "We've been singing and dancing and keeping our energy up," co-host Nicole revealed. "So we're really excited."

Usher wowed the crowd onstage, but the highlight of his night was perhaps seeing Halle Berry. "I want to thank you for being one of the most beautiful people in the house tonight," Usher told her onstage.

But after the show, Usher revealed that another lady got him going during the show: "To have Mrs. Osbourne grab my *** like that. I mean that was a moment in history itself. She could not resist."

After the show, only we were allowed backstage as Janet Jackson posed for photos. Also on hand were Nick Lachey, Mike Myers, Lindsay Lohan, who won an award for "Best Hissy Fit" in "Mean Girls" and Ashton Kutcher, who made a dream come true for one fan when he gave her his Kids Choice surfboard award.

And if you were looking for a parade of stars sporting big fashion designers, forget it. The dress code was very casual, such as Ashlee Simpson's new tattoo and funky mismatched shoes. "This is my first time to come here solo, without my sister, so it's very fun," Ashlee told us.

Tyra Banks perhaps summed up the Teen Choice look the best: "I didn't pay some stylist thousands of dollars to style me. This is straight out of my closet."

For all the details of who scored what, including the winner of the coveted "Best Lip Lock" Award, catch the Teen Choice Awards, Wednesday night at 8 on FOX.