A lot of the eye candy like the rotating cube are all Compiz.
Compiz can be used with gnome and kde.
Gnome and kde are what is called a "Desktop Environment".
A Desktop Environment is the functionally and looks of the GUI like the Desktop, Taskbar, File Manager, File Dialogs, Control Panels, etc.
So far I think KDE is more like Windows and has extra nice functions.
And gnome is like OS X with the simple design and top menu bar.
As for my OS on my main computer here what I have used before in order, though various computers I had:
Windows 3.1 - 486DX, I think it was taken to the dump
Windows 95 - Pentium, Not sure where it went
Windows 98 - Pentium ?, See Next
Windows 98SE - Same, Think I give to neighbor
Windows ME - Pentium 4 2.4Ghz, See Next
Windows XP - Same, old desktop I use as a test/guest machine now
Windows XP - Pentium 4 3.06Ghz, See Next
Windows XP/Gentoo Linux Dual Boot - Same, installed Gentoo Linux after a friend bugged me to try it, Also a laptop I'm still using
Windows Vista - Intel Core 2 Quad 2.4Ghz, See Next
Windows Vista/Gentoo Linux Dual Boot - Same, currently using
For the past couple weeks I've had Gentoo Linux running instead of Windows Vista.
So far I can't really decide which I like better.
Thus far I've been able to run both Windows Vista and Windows XP in Virtual Machines so I still can use both.
I also have Gentoo Linux on my file server and media center.
I like the control I have with Gentoo Linux but not the fact that I have to set up everything from disc mounting to compiz.
Note: Post Edited Many Times, probably due to lack of preview button, hint hint :)