What is it about the GUI that you do not like?
Gnome tries to merge a Windows-like taskbar and OS X-like hiding-stuff.
KDE has features, features, and more features.
XFCE is simple and direct, if a bit minimal, and makes accessing stuff easier (right-click desktop menu has everything), but then ignores Fitts' Law.
Enlightenment E16 is nice, but oddball, and showing its age (considering how old it is, it's pretty awesome).
Enlightenment E17 is very nice, IMO, but still needs polishing.
Fluxbox is cool, but minimal to an insane degree.
...and that's just off the top of my head.
Choice is something you have a lot of, even in Ubuntu.