"I was not expecting this," said Spears. "It's because of all of you that I'm able to do what I love to do."
Meanwhile, Ellen DeGeneres took home her 14th crystal statuette, when she accepted the award for Favorite Daytime TV Host.
"There's nothing better than knowing you make people happy," DeGeneres said in her acceptance speech.
The party started early on Wednesday, as the first awards were presented outside of Nokia Theatre when Orange is the New Black and The Walking Dead won Favorite Streaming Series and Favorite Cable TV Drama, respectively. Later, Ian Somerhalder received the statuette for Favorite Sci-Fi/Fantasy TV Actor.
Inside, hosts Kat Dennings and Beth Behrs kicked off the show with an opening sequence which included Mayim Bialik, Melissa Rauch, Ian Somerhalder, Sarah Michelle Gellar, Kaley Cuoco, Arsenio Hall, Ross Mathews and Christina Aguilera at the 2 Broke Girls' diner.
Even in their gowns and dazzling jewelry, the girls couldn't shake their waitressing characters. The actresses passed out burgers to the audience with the help of a troop of lookalikes.
The 2-hour kudos fest also included musical performances from Brave singer Sara Bareilles, country crooner Brad Paisley and rock band OneRepublic.
Check out the other notable winners below.
Favorite Movie Actress: Sandra Bullock
Favorite Album: The 20/20 Experience by Justin Timberlake
Favorite Daytime TV Host: Ellen DeGeneres
Favorite New Talk Show Host: Queen Latifah
Favorite Comedic Movie Actor: Adam Sandler
Favorite Network TV Drama: The Good Wife
Favorite Comedic Movie: The Heat
Favorite On-Screen Chemistry: Ian Somerhalder and Nina Dobrev
Favorite Pop Artist: Britney Spears
Favorite Comedic TV Actress: Kaley Cuoco
Favorite Comedic TV Actor: Chris Colfer
Favorite Action Movie Star: Robert Downey Jr.
Favorite Late-Night Talk Show Host: Stephen Colbert
Favorite Humanitarian: Jennifer Hudson
Favorite Actress in a New TV Series: Sarah Michelle Gellar
Favorite Network TV Comedy: The Big Bang Theory