I don't know about everyone else, but I NEED a good soundtrack at the gym to stay motivated. To keep going I need something with a lot of good changes, upbeat, energetic... of course, on the reverse side, "angry" music can be a good motivator too. The problem is finding a CD that you can listen to at the gym from front-to-back that maintains this energy.
Appetite used to be one of the few CDs I could rely on, but I've found if you bring the same CD too many times, it loses it's impact (as far as working out, the album is obviously still great). Contraband has done the trick a few times, but I'm cautious not to wear it out.
So what do you listen to at the gym?
On a side note - The "public stereo" at my gym is set to a station that has played "Fall To Pieces" at least once for like the past month.