Share 'mp3 managers...'

What do you use? Why? I noticed this article on iTunes alternatives when I opened Windows Messenger this morning and it got me thinking what would make the most sense. I've been using iTunes on my laptop for awhile (despite the fact I don't own an iPod) - and I really haven't tackled putting much music on my blackberry yet (it uses some version of Roxio by default). So... what mp3 player / ma...