I've been in love with the mac since the late '80s when i'd spend the summer holidays working at Bit 32 (A reseller in Liverpool UK) writing HyperCard apps for them. But i could never afford one, so i got an Amiga instead.
I've been using PC's since 1992, building almost every machine i've owned in that time, mainly because it was cheaper, but thats, no longer a consideration.
I have never been totally satisfied with my pc's. I've used Linux on and off in that time, but its never provided me with everything i needed. Also, i was a Microsoft developer (VB, ASP) for about 6 years, before switching to Java.
Im now seriously into Photography and shoot weddings on a regular basis, and use Lightroom on windows to process the images. My Windows machine is painful to use, apart from being too slow, the thought of having to rebuild (which is needed) is scary, as i cant afford to have my machine out of action for too long.
For Me, the major milestones in Windows History, where the introduction of Windows 2000, which was a pretty good release, and the discontinuation of the Windows 95/98/ME line, which were dire. Win XP did nothing for me, it was a more compatible version of Win 2k. And Vista is a complete dissappointment.
I've alway been fond of the Mac, and did own an old Powermac for a while, but only for playing on.
OSX gives me everything i need from a computer, without the problems of Windows. I can run Lightroom on it, and i can use the same dev tools i use on windows, for Java development.