Top one is Win XP with Ubuntu Human theme and the quick launch put to the top of the screen.
2nd is Kubuntu with Silicon theme with some standard desktop widgets and the Ubuntu Human icon theme.
I've not bothered posting win 7 as that's just standard 7 & my Ubuntu install is standard looking Ubuntu Human.
I think Kubuntu is almost on par with 7 on the looks department. Shame the software/hardware support is not totally up there. Case in point, my Java program needs win to run. Sucks. Might try and get it to work with Linux when i've handed it in. But i'm not going get points for making it run cross platform from my tutors though!