I added some small modification to Adwaita Dark which originally made by A. Felipe.

***Edited***
remove some junk codes.

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How to:

*For those who already have had Adwaita Dark:
Download the file, extract, and place the metacity-theme-3.xml in your /usr/share/themes/Adwaita Dark/metacity-1

*For those who don't have Adwaita Dark:
Click http://felipe.netai.net/proyectos/gnome-shell/themes/Adwaita-Dark.tar.gz to download it.

"Once you have downloaded the theme you’ll need to first ‘unzip’ the archive (right click > extract here) then manually install it as follows:

Open a Terminal
type: gksu nautilus /usr/share/themes
Move the extracted Adwaita Dark folder to the ‘usr/share/themes’ folder
Apply the Adwaita Dark theme using GNOME Tweak Tool"

After that, follow the first instruction.

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You can find more about the original Adwaita Dark theme http://www.omgubuntu.co.uk/2011/10/use-adwaita-dark-as-your-system-theme/