I prefer CDs to everything else. I have a decent set of ear phones that I use to listen to music on a discman when I'm at home and want 'full quality'. I use an mp3 player in my car most of the time now for convenience. But a big factor in that is my car's factory speakers level out the perceivable difference between mp3s and CDs.
I love having a hardcopy I can keep on a shelf with the rest of a band's releases and I love manuals and cover art. I also like to support the bands I'm into (mostly death metal) and the community as well. It's for the same reasons I prefer complete authentic game discs instead of just downloading a bunch of isos.