I sold almost all my CDs, cassettes and vinyls way back in 2004. I was moving all the time, they were a source of worry more then enjoyment as everything I listened to was on the computer.
Once in a while, I miss an album or a song, then I just buy it on iTunes or such. There are a few albums which I prefer to keep and have in the highest possible quality, but for the vast majority, MP3 is good enough. I'd rather spend an occasional $10 and not have to worry about carrying all that stuff I never use. Maybe if we had a house, it'd be different. But even then - I'm all for Feng Shui and simplicity.