My entire Dylan collection. The 2TB worth of live Dylan (WAV, FLAC, SHN & DVD), plus every album on CD, as well my vinyl & cassettes of Bob, including rares etc. Not like that would be possible, but that's what I would want out of my entire collection. I don't have many mp3s, (like 2gb maybe) and I wouldn't give a shit if they did disappear, I hardly listen to them.