Yes, all the things Subten said.
Plus... and this is gonna sound really cheesy... but for me there's just something about the "experience" of using a Mac that I prefer. It goes beyond the fact that it's aesthetically pretty. Apple really seem to have put a lot of thought into the way the operating system, well, operates! Probably really tiny things that you don't even consciously notice, like how forgiving the margin of error is when you click from a menu to a submenu - loads of little things like that, which somehow all add up to make the user experience that much smoother. ALso they've traditionally been much more consistent with their style guidelines in a way that Windows hasn't, so various tasks are more intuitive.
But yeah, looks-wise, OSX kicks a$$ too (and that's to say nothing of the hardware!) I remember when XP came out, it was clear MS was trying to copy Apple, but whereas, say, Apple's titlebar gradients were subtle and elegant, Windows used nasty stark ones - kind of like letting a kid loose with Photoshop for the first time, and they go overboard with all the effects!
(Sorry, I should stop this now, this thread's supposed to be about Vista!

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