Personally, I LOVE my Apple. I've been an Apple user ever since I graduated high school. I have never once WANTED to use Windows again. In fact, I'm on my second Mac, and I've helped my dad with trying to upgrade 2 PCs and buying 2 new PCs, and all instances have been an enormous pain in the ass.
Mind you, I'm not computer illiterate. I can upgrade them, build them, and spent a while doing tech support (level 2) for an ISP.
For one, the Apple computers don't come with as much crap on them as Windows machines do. Your computer comes with a LOT of useful applications in the consumer to "prosumer" range for all the things that most people these days would want to use their PC for (movies, music, video). All of these programs integrate seamlessly with one another and make it a very intuitive experience for the user.
We all know that if you're a gamer, you're not buying Apple. But the good part about gaming on a Mac is that by the time it gets released, you already know if it's a classic or not.
The Mac OS has style and elegance. It's not bogged down with clutter, crazy junk popping up in the taskbar all the time, constant reboots, etc... I enjoy not having to spend time every week de-crapifying my computer. Constantly dealing with spyware, malware, underware, Windows Update, security patches, missing DLL files, and the list goes on and on.
It's simpler and easier to use. People who say it NEVER crashes and that there are NEVER problems are full of it. Like ANY product, there are problems. Usually once per OS install you'll get a core dump, where your screen gets tinted grey and you get a message in about 13 languages telling you to screw yourself. So you reboot and all is fine. It's that simple. Really.
OS upgrades on the Mac also include useful things. With every major release, there are usually a handful of really cool features that are usable for all users, as opposed to Windows which has yet to really put out anything new since '95 in my user experience.
So, with your two major concerns...
1. Cost; not as much as you might think. Take a PC with similar specs, then throw in comparable software to what is included with the Mac OS and then add in all the time it'll take you to make it work together. It may not seem all that convincing at first, but when you're hours into trying to make stuff work and it just doesn't, you're pulling your hair out and want to send the whole thing back. To me, it's worth it.
2. It's a PC's world. Indeed it is. You've got all kinds of viruses and spyware on the web that will have absolutely no effect on you. You want to know the drawback? You have to go to MS's site to download Windows Media Player because embedded WMP content won't open within Safari or Firefox. You'll get a little window saying the browser can't do it, but WMP can, and asking if you want to have WMP open the file.
That's the difference. That's it. There are some file formats it doesn't support... I suppose if you like .asf files you might want to keep a spare PC around for that. Mind you... nobody uses .asf files. Every time I've had a friend consult me about a new computer, I tell them to go Apple, they don't do it, then they regret it and drool over mine instead and swear that next time they're getting an Apple.
"People who are really serious about software should make their own hardware." --Alan Kay
ETA: In agreement with MortFurd on his closing remarks. Depending on which computer you get, it is likely in your interest to buy any upgraded hardware 3rd party. I have a G5 tower and saved a TON on RAM and hard drive space by installing myself. Also, the OS upgrades are not forced, not too unreasonably priced, and are usually full of worth-while upgrades. Go onto the online apple store and lie. Go through the "education" store. Pick the local community college and get the upgrade for half price. There is no verification process. Sometimes it's good to be bad.