Zukini is a new GTK2/GTK3/GNOME Shell and AWN theme pack created by lassekongo83, who's also behind Zukitwo.
Zukini requires Unico GTK3 engine and Murrine GTK2 engine and uses a beautiful combination of metalic gray, green and glossy buttons (kind of "minty", right?). The theme is especially designed for GNOME 3.2 and is fully compatible with Unity too.
Here are a few more screenshots:
To install Zukini in Ubuntu 11.10 or 12.04, you can use the WebUpd8 Themes PPA:
sudo add-apt-repository ppa:webupd8team/themes sudo apt-get update sudo apt-get install zukini-theme
For Arch Linux, get Zukini via AUR.
For other Linux distributions, get Zukini via DeviantArt.
Once installed, use GNOME Tweak Tool to apply Zukini. You can also change the theme via command-line:
gconftool-2 -s --type string /apps/metacity/general/theme "Zukini" gconftool-2 -s --type string /desktop/gnome/shell/windows/theme "Zukini" gsettings set org.gnome.desktop.interface gtk-theme "Zukini"
When changing the window theme in GNOME Shell, you'll have to reload it to apply the new theme: press ALT + F2 and enter "r" or log out and log back in.
And speaking of Zukitwo, Georgi Karavasilev has modified Zukitwo to integrate better with Unity (light panel) - to install his modified "Zukitwo Light" version (from the same WebUpd8 Themes PPA), use the following command:
sudo apt-get install zukitwo-light-gtk-theme
First two screenshots in the post: lassekongo83