I gave the Unity desktop that shipped with Ubuntu 11.04 a try. And I didn't like it much. When I heard that the 'classic' Gnome desktop (most features of which I didn't use) was being phased out, that prompted me to switch to xfce. Fortunately, that is easy to install with Ubuntu, though I had a few hiccups there too, mostly fixed by uninstalling some gnome packages.

I've got my terminal windows, browser, PDF viewer, and that's mostly it.