CDs
Actually, not only do I not generally trade illegal copies of music, but I even accidentally buy multiple copies of the same CD! For example, I have two store-bought legal copies of The End of the Summer by Dar Williams, two of The Green World (eadem), and two of a particular recording of Bach's Mass in B minor. So I'm even sometimes buying CDs where legally I wouldn't even be obliged to.
That said, if you want my duplicate copy of any of those, let me know!