Mac OS
+ OSX is still the most stable platform and easiest to use
Is it, though?
Let's be completely honest here.
I've used Windows foverer. Well, since 1992. Up until Windows 2000, which was released in 1999 I think, Windows was ludicrously unstable and either the apps, or Windows Explorer, or both, would crash/hang/freeze several times daily. But all subsequent versions built on the NT platform, i.e. Win2K, XP, Vista and Win7, are much, much more stable, and they also have a lot of fallback technology built in, in terms of error handling and reporting. If you do get a crash, Windows is fairly informative about it and gives you the option to keep an eye out for fixes relating to this particular crash, even if the culprit is a third party.
OS X on the other hand is sort of in denial about crashes, because the system that "just works" is too aloof for that kind of stuff. Once you do get them, "informative" isn't the word I would use. Rather, it resorts to pre-OS X style error handling like throwing you cryptic codes that you have to look up with Google. We've all laughed at classic Windows error messages, but really, is "Error 102" any better? (it means "System is too old for this ROM", supposedly.)
And let's be honest, Macs do crash. Perhaps no more than Windows, but shall we say more primordially, without any sophisticated error handling. The upshot of Microsoft's screwups in the 90's is that their pants are still down, and they're constantly working on improving everything that relates to errors, crashes, security holes and all the things that gave them a bad rep in the 90's.
The introduction of Vista was quite the ordeal, due to the fact that Microsoft changed the driver model completely so that all drivers run in user mode rather than kernel mode. It took a while for hardware manufacturers to migrate to Vista style drivers. I was an early Vista adopter (2 days after the public release, specifically), and it took about 3 months before all hardware drivers I needed were sufficiently, and yet another 3 months before the system was stable. That's bad, but not too bad considering the substantial changes to the core technology.
I bought an iMac just after Leopard was released, and I gotta say it was pretty much FUBAR initially. There were grave issues, like the fact that if you saved CS3 documents (PSD etc) to a network share, the files were literally destroyed. There were tons of people who had a "BSOD" thing with Leopard where you'd get a light blue screen for ages before the the desktop showed up, if it ever did.
Perhaps the initial release of Leopard was no more trouble ridden than Vista, but then again, look at the odds. Apple has complete control of both the hardware, the OS and a fair chunk of the most popular software for the platform. Leopard only had to work on a very limited range of hardware configurations that had been done according to Apple's exact specifications. Microsoft had zero control over the hardware configurations that Vista had to deal with, there are millions of combinations of internal and external components. Microsoft's job was a billion times more difficult, unpredictable and arbitrary. So which system is tougher and more stable? Which one can take more crap thrown at it? If Leopard would hang due to some miniscule third-party add-on like DivX for Tiger not having been updated for Leopard, was that a more stable system than Vista was?
Just sayin'.