Carbonized Audion
If you’re using MacOS X, and you’re a little unhappy with the default music player (I mean, it’s nice and all, but the playlist feature leaves a little to be desired), then I would recommend picking up PR2 of Audion from Panic. You can even use your current playlists (just drag ’em on the Audion icon in the Dock; don’t double-click them, or I’m assuming they’ll open in Classic, and no one wants that).
And as a sidenote, if anyone has heard of either Adobe of BareBones carbonizing their software, let me know.