Personally, I prefer Enlightenment to anything else I've tried. E17 will be a desktop shell rather than window manager like the previous versions (E16). Take a look at the screenshots for the new version:
http://www.enlightenment.org/pages/shots.html
IceWM and Enlightenment are only window managers for X, currently. KDE and gnome are APIs that use X for gui apps. You can change the background and add icons to the "desktop" in Enlightenment and Icewm. Check out their websites and read the FAQ for more info.