SexyBack is such a classic.
2000: Bye Bye Bye, Oops!... I Did It Again
2001: Fallin', Drops of Jupiter, It Wasn't Me, Angel, Lady Marmalade, Family Affair
2002: How You Remind Me, Hot In Herre, Dilemma, A Thousand Miles, In the End, Lose Yourself
2003: In Da Club, Crazy In Love, Bring Me to Life, Get Low, Beautiful, Where Is the Love?, Cry Me a River, Rock Your Body, Fighter, Clocks
2004: Yeah!, Burn, If I Ain't Got You, This Love, The Reason, Hey Ya!, Here Without You, My Immortal, Numb, She Will Be Loved, White Flag, Milkshake
2005: Hollaback Girl, Since U Been Gone, Gold Digger, Mr. Brightside, My Humps
2006: Hips Don't Lie, SexyBack, I Write Sins Not Tragedies
2007: Irreplaceable, Umbrella, Before He Cheats (country classic), Hey There Delilah, Fergalicious, Apologize, No One, Teardrops On My Guitar
2008: Low, Love Song, Viva la Vida, I Kissed a Girl, I'm Yours, Hot N Cold, 
2009: Poker Face, I Gotta Feeling, Love Story, Single Ladies (Put a Ring On It), You Belong With Me, Party In the U.S.A.
Quintessential 00s classics? 

 Good list or no?