Medibuntu (Multimedia, Entertainment & Distractions In Ubuntu) is a repository of >packages that cannot be included into the Ubuntu distribution for legal reasons >copyright, license, patent, etc). Some of these packages include the libdvdcss package from VideoLAN and the external >binary codecs package (commonly known as w32codecs) used by MPlayer and xine. The following one line command will add Medibuntu repositories to the sources.list, install the Medibuntu GPG key and resynchronize the package index:
GNOME Shell is the defining technology of the GNOME 3 desktop user experience. It provides core interface functions like switching to windows and launching applications. GNOME Shell takes advantage of the capabilities of modern graphics hardware and introduces innovative user interface concepts to provide a delightful and easy to use experience. Availability and Status The GNOME Shell is currently in active development and while many planned features are not yet implemented it is stable enough for everyday use.
I use these setting on a laptop with a Core 2 Duo and 4 GB of ram. It might seem like overkill to tweak this system. However since it is a work machine at any time I am running Lotus Notes, VirtualBox, OpenOffice, Chrome, etc. Should you have a system with limited resources I would recommend Xubuntu for a light full-featured DE. Another option and very light on resources would be any of the open|flux|blackbox window managers.