Taylor Swift, Nicki Minaj and Katy Perry Win Big at 2011 American Music Awards!

Nicki Minaj, American Music AwardsABC/TIM OGIER

It was ladies' night at the 2011 American Music Awards on Sunday night.

Nicki Minaj and Taylor Swiftwalked away with multiple awards, while Adele, Beyonc and Jennifer Lopez dominated their respective categories and Katy Perry went home with a special achievement award.

So yes, girls rule. But the big question is: Who won Artist of the Year?

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Swift!

The "Back to December" singer, who also won Favorite Female Country Artist and Favorite Country Album, thanked her family, friends and fans...and Selena Gomez, who she called, "my little sister I never had!" Cutest. BFFs. Ever.

Minaj opened the show with a performance of her hit song "SuperBass," and after winning Favorite Rap/Hip-Hop Artist Minaj actually gave a shout-out to Swift for her support. Swift rocked out withGomezduring Minaj's performance, they even memorized the rap! Girl power, indeed!

Perry received an achievement award for being the first female artist to have five No. ! 1 single s from a single album (Teenage Dream). The singer, who rocked pink hair, performed her new hit single, "The One That Got Away."

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"It's been up and down and just exciting and overwhelming and so many things," said Lopezwho performed twice during the showafter winning the award for favorite Latin Music Artist.

It wasn't a trophy-laden night for last year's Artist of the Year winner Justin Bieber, who lost Pop/Rock Male Artist toBruno Marsand Artist of the Year. Stll, Bieber walked the red carpet with girlfriend Gomez, performed his holiday single "Under the Mistletoe" and donned skintight animal-print pants to join LMFAO onstage when they closed the show with "Party Rock Anthem." Also joining the band on stage? David Hasslehoff.

What a way to end the night!

The night was filled with performances byChris Brown,Daughtry,Maroon 5andChristina Aguilera,PitbullandMarc Anthony,The Band Perry, Kelly Clarksonand many more.

Take a look at the complete list of winners at the 2011 AMAs:

ARTIST OF THE YEAR

Taylor Swift

POP/ROCK

Male Artist: Bruno Mars

Female Artist: Adele

Band, Duo or Group: Maroon 5

Album: Adele, 21

SO! UL/R& ;B

Male Artist: Usher

Female Artist: Beyonce

Album: Rihanna, Loud

RAP/HIP-HOP

Artist: Nicki Minaj

Album: Nicki Minaj, Pink Friday

COUNTRY

Male Artist: Blake Shelton

Female Artist: Taylor Swift

Band, Duo or Group: Lady Antebellum

Album: Taylor Swift, Speak Now

ADULT CONTEMPORARY

Artist: Adele

ALTERNATIVE ROCK

Artist: Foo Fighters

LATIN

Artist: Jennifer Lopez

CONTEMPORARY INSPIRATIONAL

Artist: Casting Crowns

SPRINT NEW ARTIST OF THE YEAR

Hot Chelle Rae

PHOTOS: 2011 American Music Awards: Arrivals