Gnome 2 Look and Feel in Latest Ubuntu
If you prefer the old Gnome 2 style interface, or Classic Gnome, you can get this look and feel back in the latest Ubuntu by installing the gnome-session-flashback package. In older versions of Ubuntu, like 12.04, the package will be instead called gnome-session-fallback.
Open a terminal and run the following:
sudo apt-get update sudo apt-get install gnome-session-flashback
Logout and select Gnome Flashback session in login manager (where you enter your username and password to login).
You can select between Metacity and Compiz managers. Metacity is more lightweight, but lacks some effects. With Compiz you will get more similar experience to Unity.