My home laptop is a PC because I have to use PCs at work and it's easier if home is the same. Before I got this laptop, I was using a 10 year old Mac (pre iMac) at home and it was a pain having to switch between different keyboard shortcuts etc.
I own a PC myself, more due to the fact that I play more video games than a Mac can handle.
Otherwise, my family tends to have bad luck with PCs, and would probably do better with Macs. They own three, one of which is a Vista that's replacing an old XP that's had so many Trojan Horses on it that you'd think we manufacture them. Another used to be a Windows ME (aka the worst OS ever), but then got upgraded to an XP, with which it continues to struggle with, as it's technically not made to work an XP. This is also partly due to a series of viruses that that one managed to acquire. Basically, if it's a Windows product, we break it.