WOW, a beautiful, easy on the eyes theme, is now available for GTK3 (3.2). The WOW-2 pack comes with two GTK3 theme versions, two GTK2 theme versions, Xfwm4, Openbox, Emerald and Chromium themes.
For now, the GTK2 theme doesn't blend too well with the GTK3 version because they use some different colors, but a new GTK2 theme to match the new WOW-2 is on the way.
WOW-2 only works with GTK 3.2 (available in Ubuntu 11.10 for instance) and Unico GTK3 engine 1.0.1 for now so don't use it if you're using a newer GTK version.
If you use the window buttons on the left, copy the "metacity-1" folder from the "Left-Buttons-Metacity" directory and place it in the WOW-2 theme folder (either "WOW-2" or "WOW-2_Dark_Toolbar").
To install the theme, create a folder called ".themes" in your home directory, then download and extract WOW-2 and copy the WOW-2 and WOW-2_Dark_Toolbar folder to the newly created ~/.themes directory. Then use a tool such as GNOME Tweak Tool, MyUnity, Ubuntu Tweak, etc. to change the theme to WOW-2.
credits for the second screenshot: nale12