Wow lots of things said in this thread. Some I agree with some... well just are interesting.
Background: Apple Certified Tech and Support Pro / PC computer builder for 10 years
People get Apple because of the "ease" of use, and also that you can get service from an actual person. How many places can you walk into that your going to get a certified tech direct from a manufacturer, and that the warranty is honored at such a place?
That being said, I personally use PCs because I really like to mess with things in the OS, and I just love hardware period.
So it comes down to a few simple things:
1. Do you like to choose your hardware and upgrade? Apple for many years has been making their hardware more and more proprietary which has has blocked many people from upgrading their machines. They also have been famous for developing or adopting technologies early that don't always pan out.
2. Do you need support? Its true, you can walk into an Apple Store and get support for the first year of your machine, and for a relatively low cost you can even extend your service warranty and get unlimited calls to people that offer (comparatively) good service that is also honored worldwide (on everything but iDevices). Please do not be confused by the third part retailers that offer things like; "Best Buy's" black tie service. Best buy is not an authorized service center, but they do cover accidental damage by replacement. Many times they will not know the Mac operating system, and if they need to order a part, they have to send your enter system to an Apple service center and can take weeks to get your computer back. (This is from personal experiences from the USA Washington State "Best Buy" chain.)
3. Ease of use for the average consumer. To be honest, if your on "Tom's Hardware" I would consider you a bit "higher" then the average user because you ask questions from someone other then a salesmen. Apple's, for the new computer user, tend to have the best learning experience that is a bit more intuitive then a lot of other operating systems. I am not saying they are the best, but the certainly are good. This should not be a surprise considering they are capturing a lot of the market share. Keep in mind though, with these "ease" of learning, also means you don't have a lot of options that you would in other operating systems. For the most part, its a pretty closed system that doesn't let you "tweak" things.
Overall, I would say that you need to choose the computer that best suites your individual needs regardless of operating system. If you find that all your software is compatible, and you don't like to play with a computer much, you may want to decide to go with Apple.
If you are very familiar with the Windows OS, and you like the layout, and the prices. Why would you change? If you just HAVE to try an Apple system, goto a store and demo one. Apple also has a 30 days return policy on computers with no restocking charges. So you can also take it home with you and decide from there.
If you like Linux, and are familiar with its system, you already know its pretty darn awesome. For the "average joe", Mac's are probably the closest to Linux you can get that has a lot of the capabilities with less of the hassle of some systems. Lets face it Linux users... there is a LOT of versions out there, and not all are tailored to an average users capabilities, needs, and wants.