http://www.youtube.com/watch?v=LbVrDlVJhUQ
trust me, whenever someone tries to plant a song in your head, drop this one on them and you win
Tom's Diner by Suzanne Vega
everyone knows the song and the hook is just so damn catchy it sticks. It helps that the words of the hook are
du duh doo doot dooo dooo dooo dooot du duh duh doo du doo doot