Preference
I prefer Windows 7/8 (i know, thats terrible, but I prefer it)
mostly because I've used windows for like forever, and it seems you guys are giving it a bad image, there is no bloatware at all, and i have never gotten a virus, its speedy, especially windows 8, which boots in 2 secs on my desktop.
But, my dad started this thing too move to a mac, because he liked the macbook air, so i got a pro (because 128GB's is tiny as) and i have enjoyed OSX quite a bit, and the mountian lion made it a bit quicker, but i have had to get used to it from windows, for example the scrolling, why is the wrong way on a mac? and why does it take so long to boot! But all that aside, it is starting to grow on me, and i use it for school.
So all-in-all, i have tried Ubuntu, and other linux verities, but to put it blunt, Ubuntu is terribly unstable, on my sister's computer it started bugging out, and i had to reinstall it time over, im sure other people have not had the same experience, but i prefer not to use it.
OSX, is nice, but it is hard to use!
Windows is great!
i just prefer windows, simple fact, and preference is what makes all us computer users bias, because we all have a computer that we most use, and that is the one which we would prefer, (excuding work computers, which we might not have a choice in) so asking in a MacRumors forum, isnt probably the best way to go around asking that. Maybe you should've looked in polls/surveys.