The first question you should ask yourself is, what do I need my computer for?
If you wish to game, internet, do word processing and other common things, a PC is the easiest and arguably best answer. For more specialized uses such as music production, a/v editing, etc., I'd still say PC. However, the Mac platform has some good software for dedicated purposes like Final Cut Pro and Logic. That's about it. The price and overall versatility of Mac is unbalanced, in my opinion.
I was a long-time Mac user. In the end, I found I could do just as much and often more with a PC, often for a lot less money. I've built many PC boxes and I couldn't imagine it any other way. No regrets.
The argument about viruses and spyware are flawed. Generally, it usually takes two to tango. Viruses and spyware don't just take over your box like a highway robbery. One generally clicks something or goes somewhere without thinking and without proper protection. Would you advise going to a gunfight without a gun or vest? So why browse without a decent AV prog? To argue that the Mac removes the user's need to consider their actions while using their computer says all one needs to say.
Also, Apple has a terrible habit of pressuring you to upgrade your OS/computer by using software lockouts that is annoying. Why should I have to upgrade every five minutes to Snow Tiger, Leaping Lizard everytime I want to use a new prog?
Also, is this computer for you or to impress people? In defense of the Mac, it's a computer based around a lifestyle. The common user generally gets one because it can be somewhat idiotproof, looks smooth, and the program suites work well with each other. Usually. If you want to impress people with your cool 'puter, you'll constantly need to upgrade your Mac to the newest shite configuration to keep us with The Joneses.
With PC, it's whatever you make it. It's ultimately the most versatile option at the moment.
