^Ok, just to settle this...real world case, I got a pc made in 05, it caught a virus 2 years after that, I reformatted, didn't install an anitvirus ( cause I was being a tard) and it got another virus immediately (from download.com btw, supposedly secure site). That build has given me trouble since and I pawned it off to my mom.
Got a mac in 07, never installed an antivirus, never got a virus...even spyware doesn't put up much of a fight and I notice I also get fewer pop-ups. Now I've gotten hardware problems since I'm such a heavier user (I jerk it all day

), but I've never really had much software problems.
On that subject, the reason I have a mac is cause the UI is just lightyears ahead of windows. It crashes, it slows down, but it doesn't drive me crazy like the PC does...It's just more organized when it comes to it's chaos. Plus I like not having to deal with code and going through complicated installs cause the software just doesn't work. With macs you just drag and drop the app in and it's installed...I don't see what's wrong with simplicity and linear work flows.