Well, the GNOME team is introducing a new Fallback Mode in GNOME 3.8 that looks pretty sweet, actually. :) Also, MATE is basically a rebadged GNOME 2.
If you wanna install GNOME 3.8, including the new Classic mode, to try it out, pull up a terminal type in the following command chain:
sudo add-apt-repository ppa:gnome3-team/gnome3 && apt-get update &&
apt-get upgrade && apt-get install gnome-shell gnome-shell-extensions
However you can also give Cinnamon a shot, I used it for a while, before finally settling on (at least for now) MATE, and it's just a gorgeous desktop environment, and highly recommended. In order to install it and try it for yourself, type the command chain below in a terminal
sudo-add-apt-repository ppa:gwendal-lebihan-dev/cinnamon-stable &&
apt-get update && apt-get install cinnamon
However 13.04 has Cinnamon in the official repos.