I first switched about 3 years ago. For awhile I had both PCs and a Mac, but eventually I just wasn't using my PC anymore, so I got rid of it. I've been 100% Mac for about a year.
They do have their problems, but the issues are just far milder than on PCs.
And if you know anything about working with Unix/Linux, Macs are a joy because if you want to you can do everything from the command line just like a Unix box. (I guess technically Mac OS X is a skin on Unix)
Finally, if there is some killer app for which you absolutely need windows, you can install windows on your Mac (and dual-boot) using Bootcamp. You also have the option of using Linux emulators like Wine to run Windows programs in Mac OS X.
Mac OS X is great for people who know a lot about computers because of the Unix backend. This significantly increases the cool stuff you can do... learning Unix scripting saves so much time.
Mac OS X is great for people who are totally computer illiterate because it really is very simple and streamlined. When I let illiterate people use my Mac (always on a guest account
) they tend to be able to figure things out just by diddling around, generally because of the nice clean graphics that invite them to experiment. On a Windows box there is so much graphical noise that old people are intimated and confused, they tend to go into paralysis and get frustrated.