this OS arguement is a joke, seriously.
Linux = Network geekery & opensource horror by way of the "too many cooks" theorem, it also doesn't run photoshop, the reason that they're secure is that the average user doesn't actually use it, i'm sure if it became as widespread as windows, people would be poking security holes in it all day long.
MacOSX = Prestige machine and expense ensure that this machine stays out of the realm of the majority of the PC, like linux (apparrently OSX is built on linux to a degree) all the spyware and virii and ****e that give the PC's grief can be quite easily made for mac if people actually bothered to.
Windows = Bugged, memory hog programs, security holes, and whatnot make this OS something of a nightmare to stupid people who push the damn thing too far, i myself run a winxp system, and i haven't had it bsod NOT EVEN ONCE.
in short, i don't really care which OS is evil or what, or whether microsoft is the devil incarnate, it's time people learnt to get off their high chairs when it comes to operating systems and face reality like men.
Just to note, i know the Gimp is available to Linux, but i've KILLED the gimp trying to run it how i run photoshop, so those linux peeps who think they know better can shut it.