Windows Media Player has a decent quality list manager built in but when it comes to looking for songs you like, looking at long lists of song names and album names is really boring.
Windows Media Center does things a little better with images of the album cover but you still have to have that cover art downloaded into the folder for this to be of any use. That and it still uses the folder metaphor so it looks pretty bad, spaced out, etc.

Want to see how it SHOULD be done? Check out this awesome (Mac-only) product,
CoverFlow, that lets you browse your albums by cover art. If you don't have the cover art already,
CoverFlow can
download the art for you. Now, this is a tech demo and will most likely crash on you, but this is still one of the slickest pieces of work I've seen. Excellent job by the nameless developer at
SteelSkies.
Watch a
Quicktime video of the tool in action (for all of us jealous Windows people)