For a long time I swore by PCs and hated Macs. Now it's the reverse. Macs have such lovely graphics and don't suffer from viruses as often. If they weren't so expensive in comparison, I'm sure they'd take over.
Both - when I do Graphic Design a Mac is by far faster and more efficient, but for day-to-day internet usage, either would be fine. PCs are cheaper, so that probably has a lot to do with what someone will buy. If you're not going to work on high-end graphics, there may not be much of a point in forking out extra thousands of dollars on a Mac, except that they look so good.
I have liked PC for the last 15 years however a few years ago my kids talked me into getting an i phone.
I had always said I didnt want Apple, only because it was something new to learn.
However I now have an I pad and absolutely love apple.
However when I bought my last PC I looked at Apple and they look much nicer, however I still would have had to put Windows on for an accounting package I use and Word and Excel, so I decided that was defeating the purpose, so didn't buy the Apple.