Didn't mean to put words in your mouth. My point was that no matter the price of the PC box there's nothing you can do to escape viruses and malware except constant diligence and discipline. That's a Windows issue, not the underlying hardware.
My PC is a higher end Dell Latitude, don't recall the model number, running XP. (IT dept wouldn't touch Vista) It's about 18 months old and cost about the same as my MacBook Pro which has the same Intel processor and is the same age. In addition, I got it with an external Dell monitor, keyboard, and mouse. So far, the Latitude motherboard, monitor, and keyboard have had to be replaced under warranty. The Dell mouse hasn't been replaced, but that's probably because I use a Microsoft mouse. It doesn't dock/undock reliably so I avoid doing so. The wifi is flaky and unreliable. Most of my coworkers have similar Dells and many of them have had similar issues. I find XP to be stable and responsive enough to get my work done, but not without regular frustration with its limitations. Many times a day at work on my PC I think about how much easier or more productive I could be if I was on OS X. Perhaps our IT dept will move to Windows 7 and I'll see some improvements. The reviews I've seen for 7 indicate that it's much improved, but still not as good as OS X. Hopefully it passes muster with IT.
I saw a comparison of Vista and OS X a few months ago that I wish I'd saved. It showed a flow chart of the OS operations required for a browser to open a typical web page. The Vista flow chart was the biggest incomprehensible rat's nest you ever saw. No way you could ever make that reliable. The OS X flow chart, on the other hand, was structured and minimal by comparison. Clearly much easier to keep it reliable. And that was before Apple released Snow Leopard which was primarily an effort to streamline and tune up OS X.
While not perfect, I still contend the Chevy/BMW analogy is a good one. Chevy offers everything from basic transportation to the high performance Corvette. Reliability will usually be acceptable, but is not top notch. Not sure how to make an analogy for the virus/malware issue. How about Windows is like having a huge flock of grackles following you everywhere you go trying to crap on your shiny Chevy and you're constantly having to chase them away? And, for some reason, grackles couldn't care less about BMWs.
Are Macs theoretically vulnerable to viruses and malware? Yes, but there's also the fact that by and large virus/malware perps don't bother. Also, the latest version of OS X includes virus/malware protection in addition to fixing vulnerabilities. The list of threats is very small so it doesn't take much for Apple to include it. It remains to be seen how they respond if the threat increases, but it's clear they've laid the foundation to address it if necessary.
For me, the choice is clear: Mac.