It is not just OS X, I would even take System 7, Mac OS 8, or Mac OS 9 over any of Microsoft Windows' current offerings, any day of the week. I was a big fan of Classic Mac OS, and I refused to switch over to OS X for the first few years until they finally got all of the bugs worked out (late builds of Jaguar into Panther). I found Mac OS 8 and OS 9 to be very productive operating systems in their own right, and much more powerful than Windows, both simpler and more elegant. I have always felt 'out of place' using Windows, and feel that it is a 2nd rate operating system, still is...I refuse to use Windows!
I cannot understand why all of these PC manufacturers that strive to make great hardware, make sleek and innovative machines, would load such a CRAP operating system on their computers and try to sell them running this ********* which is Windows. Come on, it's 2012 -- there are many Linux builds that are more elegant, more powerful, sleeker, and easier to use, add to that more stable than WINDOWS. This, I don't understand!
Edit: Okay, I will agree that Microsoft has considerably improved the stability of Windows -- but still, it's bloated, ugly, and a POS to use. Getting hardware to interface with Windows can still sometimes be a royal pain in the rear. Troubleshooting Windows is no fun. Part of the great things about Macs is, they just work, they are extremely easy to use, the OS is highly customizable and very powerful, and hardware interfacing is a breeze. The device compatibility may not be nearly as big as the Windows ecosystem, but for the hardware that is 100% Mac compatible, it is a breeze to use. One of the drawbacks with Macs (many people express their frustrations) is the lack of video card compatibility (with Mac Pro). Many of the video cards, PCI cards, and PCIe storage solutions/hardware interfaces are simply not compatible with the Mac. Apple has a very specified realm of hardware that they 'allow' to be used with Mac and will not support anything outside of this -- so yes, the Mac is a *very* closed system. Apple has their own firmware they use with all their machines, and they use EFI firmware. This is the way of 'closing' the system and preventing hacking/unauthorized manipulation of the hardware. Many PC folks and DIY-ers criticize the Mac based on this, and believe Apple is 'screwing' their customers by making the Mac a 'closed' system like they have. So the ultimate decision is a trade-off, having a very stable and rock-solid system, but having very little leeway to tweak the software or hardware to meet your custom enthusiast needs.