Gnome-Fallback

In Ubuntu 12.04 Ubuntu defaults to the Unity interface.
I'm a creature of habit and have grown acustomed to the gnome classic interface, so natuarlly I want to make that my default desktop.

Install Gnome Fallback

sudo apt-get install gnome-session-fallback

Setting the default Session

Gnome Classic

/usr/lib/lightdm/lightdm-set-defaults -s gnome-classic

Gnome Classic (No Effects)

/usr/lib/lightdm/lightdm-set-defaults -s gnome-fallback

Reference

http://www.tejasbarot.com/2012/05/17/howto-change-default-user-session-ubuntu-12-04-lts-precise-pangolin-login-session-desktop-environment/