I used Windows all my life then I bought an iBook G4 for Uni and loved it. Now I have an iMac and I will never go back to Windows unless Microsoft pull something out the bag and Apple do something disastrous.
I still have a Windows PC but the Mac beats it in almost every way. I still use Windows every day at university and to test web pages on but I can't wait to get back onto my Mac.
Stuff like expose, dashboard, iDisk, built in DVD player, never got any spyware, malware, viruses, it's easy to network. Never had to format or restart or uninstall/reinstall a program. Plus all the great programs and beautiful GUI. Now that I can boot into Windows if I need to it's great. There's a reason it's the industry standard in creative, design, music industries.
Plus I downloaded this program the other day and now when I move my mouse pointer to the edge of the screen on my iMac it teleports across to my iBook so I can use the mouse and keyboard with it. Then I can teleport back when neccessary. I can drag files across as well. Amazing, and free.
And it's no more expensive than a Windows PC really. Show me a system with 1GB ram, 2.16GHz Intel Core 2 Duo, 160GB hard-drive, operating system, webcam, keyboard, mouse, monitor, iPod all in a beautiful package for £1,200.
I still enjoy using Windows PC's. There's nothing THAT bad about them but I do think Mac's are better overall and I will continue to use them until that changes.