Delicious Library is a program that allows you to catalog your entire library of books, movies, music, and video games. You can categorize them anyway that you want. It can make recommendations (just like amazon) based upon similar items. And, it even allows you to keep track of who and when you lend things to your friends.
Unfortunately, it's not available on PCs. (Sorry McGill)
I've been trying a demo version this morning, and it's pretty cool.
Here's a screenshot...