* The Black Eyed Peas. This American hip hop group released their fifth studio album, The E.N.D., in 2009, which was a huge commercial success. The album sold over 11 million copies worldwide and featured hit singles such as "Boom Boom Pow" and "I Gotta Feeling."
* Lady Gaga. This American singer released her second studio album, The Fame Monster, in 2009, which was also a huge success. The album sold over 15 million copies worldwide and featured hit singles such as "Bad Romance" and "Alejandro."
* Taylor Swift. This American country singer released her third studio album, Speak Now, in 2009, which sold over 10 million copies worldwide. The album featured hit singles such as "Mine" and "Back to December."
* Eminem. This American rapper released his sixth studio album, Relapse, in 2009, which sold over five million copies worldwide. The album featured hit singles such as "We Made You" and "Beautiful."
* Michael Jackson. Although Michael Jackson died in 2009, he remained the highest selling artist in 2009. His album, This Is It, sold over 10 million copies worldwide. The album featured hit singles such as "This Is It" and "Earth Song."