I am a Windows user who is now a (mainly) Mac user. It was more the hardware (Macbook Pro) that attracted me more than the OS. They cost more than a Windows laptop, but you can see the engineering differences and build quality.
As for the OS, Windows 7 and OSX each have their plus and minus issues (though I think OSX's graphics and fonts are slightly more appealing). But there are little things about OSX that I do like. For example, a simple pulldown menu for "Location" for different network card configurations. Or the fact that I can rename or move files in the OS for certain applications (like iTunes) and the app still knows where they went to.