Does Apple II Plus to Microsoft DOS count??? lol
In all seriousness though, I just recently bought an iMac just two months ago, and I use it at home almost exclusively now. I still use my PC's, but not nearly as much, unless I need Windows for a certain piece of software, or to play a game that isn't available for Mac.
The biggest reason for the switch was Photoshop, After Effects and Premier Pro. I'm still amazed at how much better they work on a Mac compared to my PC.
Still, I can't say that one platform is overall superior to the other. Probably 98% of what I want to do with a computer can be done on a Mac when it comes down to hardware. But when you factor in software, there are definitely some software gaps on the Mac, as least for me. There are definitely reasons that I'll never stop using PC's until those gaps are filled.
I do, however, LOVE my 27" iMac though!