I have both and wouldn't choose to do without either. (MacBook, ipad, ipad mini, pc desktop allinone, 2 pc laptops, one of which has a lot of mods & is purely for streaming British TV shows
so stays permanently hooked up to my tv).
I love the user-friendliness of apple products & how they all integrate together, but I really don't like the limitations Apple places on you with what you can do with a product you've bought, so I jailbreak them as soon as they are out of warranty.
I loved loved loved Windows XP. My previous desktop had Vista....what a joke...that almost put me off PCs for good. I didn't even keep the thing a year. I've played on windows 8 a bit, don't love it, but can see where they are going with it, but without a touchscreen puter, it seems pointless.
One thing is with Apple you just have very few products to choose from so picking one out is fairly easy, but with PCs you have so many brands. Don't know about others, but I've not found one that is so great I'd stick with it. I've had bad HPs & Toshibas, and my current desktop is an all-in-one DELL that I wouldn't recommend to anyone. Been pretty happy with my Sony Viao though.
As to viruses....there's lots out there for macs too, so make sure you run some good protection no matter what you choose.