Anstat
Some of you may remember this icon set I was working on from 2006-2008 but (surprise!) never finished. It's actually fairly complete, even though it mostly consists of lots and lots of variations on the main folder and drive icons.
Many of the icons aren't fully finished (especially the 512 px sizes) and they obviously look a bit dated. Periodically I still get people asking for them though so I went through all my PSDs and exported the latest versions. Just don't hold your breath for any updates.