you probably would want fiesty fawn (7.04)
what you would want to make it less boring once its installed:
first off you need to get rid of the ugly color of the top and bottom bars, so right click in an empty area on a bar, and go to "properties" then in the properties window click on the "background" tab, click the "solid color" radio button, then slide the "style" bar around until you are satisfied with the transparency. if you want the top and bottom bars to be exactly even in transparency, you can use the arrow keys to slide the bar exact ammounts.
then go to
GNOME-Look.org and click on the "metacity" section.
find one you like, download it, unzip it, then go into "system", "preferences", "theme" and drag the theme folder you unzipped and click the "save theme" button and save it. you should have a new window theme, instead of the orange that comes with ubuntu.
if you don't like the icons, you can also get an icon theme from gnome-look.org
now for the desktop effects.
"System", "Preferences", "desktop effects" then click "enable desktop effects", and make sure both the 3D cube and wobbly windows are checked.
then go into synaptic ("system", "administration", "synaptic package manager")
and type: compiz
check in the boxes with "mark for installation" named: "compiz-extra", "compiz gnome" (if its not already green), "compiz-plugins", "compiz-gnome-manager" (if its not already green)
when you check some boxes to be installed, it might tell you that you to install need an additional file named libsomething or something like that. just click "yes" and it will check those for you also.
once they're all checked, click the "apply" button and wait. with all those installed, it might be a good idea to restart, so restart your computer.
once its booted up again, in the "system", "preferences" menu, there should be one called "GL Desktop", that wasn't there before. open that.
in GL Desktop, click on the "workspaces" tab and change that to as many as you want. i think the default is 4 isn't it?
to activate the cube (or whatever shape you have) you can either hold down ctrl+alt and click anywhere on your screen, or in the bottom right, you will have four little squares to click, and it will change the desktop number.
and finally, if you liked the transparency of the windows in vista, you will like this:
in the GL Desktop window, in the "configuration" tab, change the "metacity theme opacity" to "0" and the "active window opacity" to "33" now you have GLASS WINDOWS!!!!
hope that helps