KDE definitely -- the kicker, other panels, good clock alternatives (the default in Kubuntu and Knoppix looks like it was inspired by those electric National Debt counters or something worse, but that's too easy to change). and the fact that you don't have to jump through a whole lot of hoops to switch the sides on your (max, min, close) window buttons. I was a Mac user from 1992 to June of last year (G4's power supply went out) and every once in awhile I get the yen to window-box the "old way".