Here is a link to the page hosting downloads of the Ubuntu Gnome Shell re-mix. This is a version of the Ubuntu distribution that uses the Gnome Shell desktop instead of the default Unity. This is a more customisable desktop for the Linux desktop user. Of course you can just install the KDM login manager with this command: sudo apt-get install kdm and then the Gnome Shell desktop may be installed thusly: sudo apt-get install gnome-shell. Then you have the Gnome Shell desktop installed and a proper login manager that is better than the default Lightdm option. Ubuntu is not a bad distribution when you install some extra packages to replace the default desktop with something nicer. With some extensions installed; the Gnome Shell desktop is really a nice option for your default desktop; I just wish that the search ability built into the Unity dash was available in Gnome Shell. That would make the desktop even better. But the ability to install different desktops in Ubuntu is the one thing amongst many that makes it better than Windows. You can install E17 as well if you wish; just type sudo apt-get install e17 and the new Enlightenment desktop environment will be installed for you. E17 is the new version of the venerable Enlightenment desktop that used to be on many Linux desktops.
There is a Linux distribution called Elive that comes with the new E17 desktop as a default; this has a nice desktop theme that is now available for any Linux distribution.
Download this here: http://www.securitronlinux.com/debian-testing/elive-default-theme-available-for-latest-enlightenment-e17-build/. This theme is very good and the overall feel of the latest E17 desktop in Ubuntu is one of reliability and speed. If you are running Ubuntu on an older computer; then the E17 desktop would be a faster option; that is more attractive than the Xfce or Lxde desktops.