LMFAO song Party Rock Anthem top track on iTunes UK
LMFAO track Party Rock Anthem was the best-selling song on the UK version of iTunes this year.
Adele's Someone Like You finished second with Maroon 5's Moves Like Jagger in third place.
Making up the top five are Jessie J with Price Tag and Pitbull with Give Me Everything.
Adele's album 21 was the most downloaded of the year after being named the biggest-selling album of the century earlier this week.
Her debut album 19 was also the 11th biggest seller of the year, almost three years after its release.
The British star, who is recovering from throat surgery, was also named artist of the year by the iTunes editorial team.
She said: "I'm thrilled to top the iTunes album chart of 2011 and to be iTunes artist of the year is just amazing."
Ed Sheeran was named new artist of the year.
There was more success for Adele in America after it was announced she had the top-selling single (Rolling in the Deep) and top-selling album of the year on the US version of iTunes.
She beat the likes of Katy Perry, Bruno Mars, LMFAO and Cee Lo Green to the singles title.
Foo Fighters' seventh studio album Wasting Light was named US album of the year, while rapper Nicki Minaj was given the breakthrough artist of the year prize.
LA indie rockers Foster The People were handed song of the year for Pumped Up Kicks.
Meanwhile, David Fincher's 2010 film The Social Network topped the best-selling film list, while Doctor Who was the top-selling television series.
Angry Birds was named top-selling paid app for the iPhone and iPad.
Biggest-selling iTunes singles of 2011 in the UK:
1. LMFAO - Party Rock Anthem (feat Lauren Bennett & GoonRock)
2. Adele - Someone Like You
3. Maroon 5 - Moves Like Jagger
4. Jessie J - Price Tag (feat. B.o.B.)
5. Pitbull - Give Me Everything (feat. Ne-Yo)
6. Bruno Mars - Grenade
7. Adele - Rolling In The Deep
8. Jennifer Lopez - On The Floor
9. Drake - What's My Name?
10. Rihanna - We Found Love (feat. Calvin Harris)
Biggest-selling iTunes albums of 2011 in the UK:
1. Adele - 21
2. Rihanna - Loud
3. Bruno Mars - Doo-Wops & Hooligans
4. Ed Sheeran - + (Deluxe Version)
5. Chase & Status - No More Idols
6. Jessie J - Who You Are (Platinum Edition)
7. Lady Gaga - Born This Way
8. Tinie Tempah - Disc-Overy
9. Coldplay - Mylo Xyloto
10. Various Artists - Now That's What I Call Music! 79