I threw out all my old CDs, but I've since converted all the stuff I wanted to keep to FLAC and everything is digital now. I really, really hate clutter.

I've also had to move house a lot over the years, so cutting down anything you have to haul around is a good bet. Learned the hard way some 15 years back when I had to leave my books behind on a cross country move and I could only take what fit in the back of my hatchback. I moped around sad about it for a while after the move and my wife insisted I get a Kindle. It was life changing. Now all my books, games, and music are digital, stored on my NAS in RAID5, as well as with offline backups for most of it.