Some more highlights of the decade:
"Yeah!" - Usher feat. Lil' John & Ludacris
"Rock Your Body" - Justin Timberlake
"Lose Yourself" - Eminem
"Crazy In Love" - Beyoncé feat. Jay-Z
It was also the decade where everyone wanted to "do" Mashup:
"Freak Like Me" - Sugababes (taking on both Adina Howard and the Tubeway Army)
"All Summer Long" - Kid Rock (melding Warren Zevon and Lynyrd Skynyrd)
"Genie in a Bottle" - Speedway (citing the famous Christina Aguilera and The Strokes mashup)
"Being Nobody" - Richard X vs. Liberty X (the same guy behind the Sugababes track, this time merging The Human League and Rufus & Chaka Khan)