VH1 made a list of the 100 Greatest Songs of 00s and named Beyonce's 'Crazy in Love' featuring Jay Z #1 song of the decade...
Here's the top ten
10. 50 Cent / In Da Club
9. Mariah Carey / We Belong Together
8. Jay-Z ft Alicia Keys / Empire State Of Mind
7. Justin Timberlake ft Timbaland / SexyBack
6. Kanye West ft Jamie Foxx / Gold Digger
5. Kelly Clarkson / Since U Been Gone
4. Eminem / Lose Yourself
3. Lady Gaga / Poker Face
2. OutKast / Hey Ya!
1. Beyoncé ft Jay-Z / Crazy In Love
full list here