i'm with TW on this, my favorite song changes nearly every other day. I used to have a nice collection of CD's, but they were all stolen.

so i stopped buying them, and now just download music from the network at my school. So with just short of 5,000 songs, and music playing non-stop in my room, i'll have a new favorite song every couple of days.
Right now, it's Wish i had an angel by nightwish
Yesterday it was Baba O'riley by the who
Saturday i distinctly remember listening to someday my prince will come by miles davis at least 49 times.
and during finals/study time, my favorite song is the 1812 overture by Tchaikovsky. when i pull up iTunes and sort music by total times played, 1812 is my top played song at 379, with arizona stand by lucky boys confusion in second with 159.