Well. Looks like I'm gonna be a dissenter.
I don't understand the Ignition love. What's so special about it? I thought R Kelly was a laughingstock around here anyway?
I also don't get the B.O.B. love. Doesn't do anything for me(and I only just listened to it for the first time about twenty minutes ago after seeing it atop this list - was never an outkast fan). I think Hey Ya is much better, and I've only come around on that recently(I didn't like it at all when it was everywhere in 2004). To say that B.O.B. is the best song of the decade is absolutely, unequivocally insane, imo.
On the subject of hip-hop, how does The Marshall Mathers LP, absolutely one of the hugest hip hop records of the decade, get nothing on this list? The Real Slim Shady? The Way I Am? Stan? I take any of those three over B.O.B. any day of the week.
Other stuff that I think should have made it:
Coldplay - Clocks
Arcade Fire - Wake Up
Arcade Fire - No Cars Go
Muse - Time Is Running Out
Muse - Knights Of Cydonia
Probably some other Muse tracks
Green Day - Boulevard Of Broken Dreams
Smashing Pumpkins - Stand Inside Your Love
R.E.M. - All The Way To Reno(You're Gonna Be A Star)
Sigur Ros - Untitled 4
Travis - Love Will Come Through
A bunch of Radiohead stuff(namely How To Disappear Completely, You And Whose Army, I Might Be Wrong, Life In A Glass House, There There, A Wolf At The Door, All I Need)
And yes, some U2(namely The Ground Beneath Her Feet, Beautiful Day, and Fez-Being Born)
Among others.
Not a terrible list, a lot of good stuff on it, but I don't think it's a great list either.