I’d also put MacOS X above Gnome, but below Windows primarily for gaming reasons as well. I can’t say I’ve made a serious effort to get by with TWM or any minimal manager before. I can live by a command prompt, but in a GUI, I want a fully functional GUI.
I’m a KDE man myself. I’ve been using KDE4 on 11.0 since beta 3 on my laptop with only one problem: smb:/ is crashing dolphin and konqueror. No idea why though, it might be a samba problem.
I’ve also been having a look at xfce on 11.0RC1. It has come on really well since I last had a look at it.
Gnome just doesn’t cut it for me.
Gnome.
KDE3 isn’t that bad, but gnome pwns it IMO
KDE4 needs some refinement(4.1), but gnome pwns it too
Here’s my look on things:
- Gnome
- KDE
- Xfce
- OSX
- *box
- Bash
- Xp
- win98
- win95
- DOS
- Dog [insert drool/release/etc here]
- Vista
You missed out dog turd above Vista
fixed it 
KDE 3
KDE 4
XP
E17
OSX
Gnome
xfce
Win2k
Bash
Win 98SE
OS/2
Amiga OS
Vista
System 7
Win 95
Geoworks
DR-DOS
MSDOS
Win 3.11
WinME
MS Bob