save2600, agree with most of your points, Macs just work for obvious reasons. But this "...adding new hardware to one or replacing its power supply, mainboard or other cheaply made 3rd party component that just blew..." is nonsense, don't you think? What's the problem with the fact that you can add new cheap hardware to your computer? Plus, it's not like you have to, nobody's forcing you. And that generic PC hardware malfunction more often? It may well be true if you buy on the cheap (which you cannot with Mac - again, an option), but the truth is you can buy quality components and still spend significantly less than on a comparable Mac.
Edit: I also cannot agree that Apple chooses quality hardware as persia says. It's not my experience, but I've heard a lot of people say that you should never buy first revision of anything Apple, because there are always problems, especially with their notebooks. Although I suppose the situation is probably much better today than it was let's say 5 years ago. They have nice cases, but quality components? I think they use mostly the same generic hardware as any PC builder today. Drivers and compatibility, that's a different story, of course, in this regard they are hardly challenged by Windows, logically. Today's Mac is a stylish case and OS - my $0.02.