IMHO, the difference between CD & Vinyl is not unlike the difference between Solid State and Tube amplifiers. I had always wondered about it too until someone gave me a bunch of old records. After a while I bought a turntable, some 80's model Polk Audio speakers and a nice Marantz amplifier. Jesus dude... it just sounds so frickin' awesome. It seriously makes a digital recording sound sterile. The sound is very warm and organic, not to mention the wonderful allure of the occasional hiss and pop. Few things make me as happy as the sound of the needle first touching the record. Pure bliss.
For about two years now I have been collecting my favorite albums on vinyl. You haven't heard real rock n' roll until you listen to AC/DC's "Back in Black" on vinyl. seriously.