Mac this, Mac that... *sigh*
LINUX PEOPLE!!! lol
Actually, I can't really say anything because right now my system is a quad-boot into Ubuntu, XP, Vista and Mac 10.4.8 (tiger) so... who am I to talk ;-)
Funny though, the one I use the most is XP for gaming purposes unless it's a DX10 game, but otherwise I prefer Ubuntu. Weird how that works.
Oh yeah, and XP is the one that has a stupid pop-up issue that no anti-virus program finds, just the child viruses it downloads.
*Popups show up out of no-where, and I've got spybot Search and Destroy, which will find the child software, but can't find the root software or registry keys and delete them, and I'm far too busy (read: LAZY) to do it manually*
P.S. The kernel of Mac is loosely based on various versions of Unix and Linux, which is why the command prompt (terminal) and bootloader/bootcamp in Mac look exactly the same.