"Music has never been ultimately about competition," she said as she accepted the top prize via satellite from London, where she is to perform Monday. "To even be mentioned in a category with Michael Jackson, who we will miss and love forever, is an unimaginable honor."
Swift was also named favorite female pop/rock and country artist and favorite adult-contemporary artist. Her album, "Fearless," won favorite country album. Jackson was voted favorite male artist in the pop/rock and soul/R&B categories. His 2003 greatest-hits album, "Number Ones," also won favorite album in both categories, bringing his career AMA total to 23, making him the most honored artist in AMA history.
The victories came during a performance-filled show that closed with an S&M-themed, sexually charged performance by Adam Lambert (which included him shoving a male dancer's face into his crotch).
Jackson's trophies were accepted by his brother Jermaine, who paid tribute to his late brother by wearing glittery white glove. He thanked "Allah for blessing my entire family" and named each of his brothers and sisters.
He said the message of Michael, who died in June at age 50, is more important than any award.
"The message that Michael had will live on forever," he said. "He saw good in everyone and he wanted everyone to do good. He always started with love."
Jackson's victories were among the highlights of the evening, which also featured an eye-popping performance by Lady Gaga, a special award for Whitney Houston and that jaw-dropping number from Lambert, who traded in his "American Idol" image for sex, leather and chains Sunday.
On an elaborate set filled with stairs and platforms, Lambert fondled a female dancer, kissed an androgynous band mate and led two leather-clad men across the stage on leashes as he sang the title track from his new CD, "For Your Entertainment," out this week.
Lady Gaga, wearing a "Alien"-inspired headdress and vest filled with lights, performed songs from her new album, "The Fame Monster," also due in stores this week. She used her microphone to break into a glass case where a grand piano stood. It caught fire when she sat down to play.
Whitney Houston made a resplendent return to the AMA stage with an elegant performance of "I Didn't Know My Own Strength." The 46-year-old entertainer also received the International Award of Excellence for her musical and philanthropic contributions. She dedicated the honor to her daughter, music mogul Clive Davis and "everybody who supported me."
The American Music Awards honor the year's top-selling artists in eight popular genres, and fans voted for the winners online. But even more than awards, the AMAs are about performances, and more than a dozen of them filled Sunday's show.
The Black Eyed Peas, voted favorite pop/rock band, energized the crowd when they performed two of the year's most popular hits: "I Got A Feeling" and "Boom Boom Pow."
Rihanna returned to the AMA stage, sporting blonde hair, a skintight, white peek-a-boo bodysuit and a tattoo down the front of her neck that read "Rated R," the name of her new album, out this week.
Janet Jackson opened the show with a medley of some of the biggest hits from her long career -- all tracks that appear on her new greatest-hits collection, also called "Number Ones."
Alicia Keys and Jay-Z dueted on their ode to New York City. Shakira was flanked by a dozen dancers in tiny black bodysuits as she sang her new single. Kelly Clarkson performed a stripped down version of her hit "Already Gone," backed by a string quartet.
Jennifer Lopez added a boxing motif to her dance-filled performance, but she slipped during a tricky move and landed on her bottom.
Green Day lead singer Billie Joe Armstrong confessed backstage that the show left him star-struck.
"When you see all the talent that's in the room" like Jay-Z and Lady Gaga, he said, "it's like holy moly, these are huge people."
The band was voted favorite alternative artist. Other winners Sunday included Jay-Z, wife Beyonce, Keith Urban and Rascal Flatts.