I could probably boil down the things I like about OS X into a few points:
* Less rebooting. Every other security fix, patch and application in XP requires a reboot to install. It's irritating, time-consuming and pointless. Also, frankly, OS X locks up with a lot less frequency than Win XP - whether this is related to the Windows registry (as someone pointed out above), or some other issue is irrelevant. The BSOD is a common occurrance once a Win XP install gets to be about 6 months old.
* Speaking of security fixes and patches, OS X has a stable core. When it gets right down to it, Windows is contrived and always has been from the days it ran on top of DOS. It was never meant to be an OS, just a convenient way of looking at files on your computer. It's like hot-rodding a Yugo. At least Free BSD (Darwin) has a number of years behind it as a stable OS, and this makes a difference WRT how easily the OS is exploited by all sorts of virii/malware/spyware.
* iLife - a wonderful collection of applications. They've really grown on me. Heck, I know semi-pro musicians using GarageBand for all their tracks. As a whole it really knocks the socks off of what's available on Windows.
And, yeah, there's some stuff that's hard to work around on Macs: Safari (Apple's browser) sucks, there's no equivalent to dictation software like Dragon NaturallySpeaking, you'll have to re-buy software, using an iPaq with a Mac is like slicing bread with a rock (this includes Missing Sync), there's limited sync compatibility with a lot of mobile phones, more limited game availability (so I hear), and software vendors act like owning a Mac is akin to keeping your children chained to a pole in the attic. But as a long-time Windows user, I've found that with a little creativity, deeping developer support, and willingness to do some workarounds these issues aren't insurmountable.
