I'm a pagan.
I have a Macbook Pro that hasn't been booted in OSX since I installed Windows 8 when I got it :p
Windows isn't perfect, but I've had less problems with Windows than I've had with OSX and various Linux distros. I've spent two days changing the resolution on a Linux machine when it output to a composite cable. And various other tasks that would be trivial in Windows just aren't implemented yet in Linux. For the most part, it's not the fault of the Linux kernel itself - it's just the average linux application seems to be of a worse quality than a similar windows application (or rather: the selection is much larger, making it easier to find a good one). My experience with Linux is summed up by the quote: "Linux is only free if your time has no value".
That being said, I do own a Synology NAS, which runs on Linux.
OSX is ok, I suppose, if you're doing basic tasks. But as soon as you venture into uncharted territory, the beast that is Unix shows its face, and everything becomes much more complicated than it should be. It is relatively user friendly for basic users, but as a power user, I am annoyed by the abstractions like dragging a new application into the applications folder to install it, and dragging the DVD-Drive into the bin to eject it. (Makes even less sense for mounted .isos).
Windows has it's quirks, but it is easier to find an answer online as there are a lot more people using it.
The only system I've ever encountered malware on, or been hacked on is the Linux device, which I find quite hilarious.