Windows XP, apart from fixing a load of bugs, updates, and all that stuff, Windows XP really started to have some 'shine' about it.
Now that is Gnome, not the fact that it is an 'old' Desktop Enviroment but that it gives you a not to slick but not to shiny set of desktop effects.
But, then Windows ista and then Windows 7 came along. Now, that is where I would put KDE, a nice, shiny, kind of cool desktop enviroment.
Now me, personally prefer KDE. But, it doesn't run fast on my machines, and doesn't have a fast startup speed(yet), so I stick with gnome, or xfce or even icewm sometimes. Yes, I would prefer KDE, but that's for a faster PC!