makes me think of a subcategory question - what album have you bought in the most different media
we should also figure out a special prize if someone bought music both on 8 track and mp3
I actually don't know my answer but i'm going to guess Purple Rain
Probably Rush - Moving Pictures. My aunt gifted me her copy that she bought when it came out (which I then lost somehow), then I bought the cassette, then the CD, then the album again, then downloaded it on iTunes.