If I had to listen to one song on repeat for the rest of my life it would be Roxanne, the Moulin Rouge version. Ewan McGregor's voice has so much emotion that sometimes when I'm being ridiculously emotional (read every other day) it can even make me cry. I can attest to the fact that I wouldn't get sick of it because I in fact have tested this theory. My senior year of high school my jazz choir performed at the Santa Cruz Jazz Festival (we did quite well!) and you know how music nerds are. A trip to sing means vocal chords must be in use at every possible moment! On the drive back Roxanne and Creep (by Radiohead) were the most requested songs in the car. And luckily my mom indulged us and was oh so patient.
P.S. The movie version is better than the CD so here is a little treat :)