Gstyle is a new full Gnome theme manager with some really great features which I am sure you will love if you like to customize your Desktop look constantly. Gstyle can automatically download and install wallpapers, Xsplash, GTK themes, icon themes, full themes, mouse pointers and more from gnome-look, deviantart, customize.org and others, or directly from the software source.

GDM or GNOME Display Manager will easily allow anyone to fully customize the login screen theme without having to use the command line.There are tons of ready-made, user-submitted GDM themes available that we can just download and effortlessly install.

Gnome Art is an art website which allows you to download and install various items such as icons, backgrounds, desktop themes, login window theme and gtk engine. This website comes with a very interesting application which is in the Ubuntu repositories. If you want to install it, run this in a terminal:

François Vogelweith is the author of zgegblog, a site that maintains a collection of great GNOME themes. Balanzan (translated: Balance) is one of its most popular creations, a very comprehensive theme based on Ubuntu Jaunty Jackalope, which contains a wallpaper, logon theme, Emerald theme, controls and icons.

Been a long time for changing Avant window Navigator theme, found really cool collection on deviantart, you will find many themes appropriate for your desktop and installed themes you have even it was dark theme or bright theme.

Found a lot of themes while surfing websites for the best Dark Gnome Themes, those themes will required GTK 2.x , Emeraled, compiz for extra visualization. you can make your own customization using Emeraled or basically customize theme from Appearance Preferences.

GNOME Shell is a component of GNOME 3.0, the next generation of the GNOME desktop environment scheduled for release in March 2011. We did introduced Sonar, Elementary and Ambiance GNOME Shell themes before and we have one more to showcase, Equinox GNOME Shell theme.

Bisigi themes had always been my favorite. Initially they started of with 9 themes and now the full set includes 12 mind blowing themes for Ubuntu gnome. And the most interesting part is that, you can download these themes directly from Synaptic.

GDM is the GNOME Display Manager, a graphical login program, which provides a simpler alternative display manager for the X Window System's XDM. GDM is released under the GNU General Public License (GPL). The X Window System by default uses the XDM display manager. However, resolving XDM configuration issues typically involves editing a configuration file.