Macs are great things, I have an iPhone and I'm typing this post on a Mac Mini right now, in fact I have a couple of Macs along with about 9 PCs, 3 servers and a NAS in my house. I love my Macs, they are easy to use, have a lovely interface (OSX) and you don't have to worry too much about viruses as nobody bothers to write any for Macs because they only make up a tiny portion of the number of computers connected to the Internet. In fact I persuaded my Mum and Dad to get one years ago as I was sick of fixing and supporting their old Windows 98 based PC and in 5 years all I have had to do is upgrade the RAM and occasionally update the OS, as others have said here they just work and they are joy to behold, both to use and to look at.
However, and it is important to stress this, PCs have come a long way and are not what they used to be. The introduction of Windows 7 has changed things quite dramatically, Windows just doesn't crash anymore, well, no more than my Mac does (yes, Macs crash too). The old blue screen of death is a distant memory and you shouldn't consider unreliability as a factor when looking at buying a PC, as a decent PC from a big manufacturer will be just as reliable as a Mac, just make sure it's running Win7 and has some decent antivirus software on it (Avast is free and works just fine). The other big issue is games, if you like playing games on your computer you will need a PC, Macs are still light years behind and even hard core Mac fanbois have "secret" PCs stashed around for playing games (yes, even Jason Bradbury). The other big difference is you don't get the lovely shiny packaging that Macs are wrapped up in and, most importantly, the price. Macs are still hugely expensive for what they are, in fact Apple are the only big client computing hardware vendor that still draws a reasonable profit from client computer sales, whilst the big players like Dell and HP pretty much make nothing on home computing devices. One thing to bear in mind, however, is that they hold their value amazingly well. A 2 year old PC is worth next to nothing whilst a 2 year old Mac is still a very saleble item, just have a look on eBay.
In essence, both machines will do everything you could ever want them to and both will do certain things very well, just not the same things. Overall, there is very little between Windows 7 and SnowLeopard to be honest, they are both great operating systems and beneath the skin PCs and Macs are basically EXACTLY the same these days. The only real problem to watch out for is the whole Mac cult, and it is a cult. Steve Jobs even got some of them to buy this weird giant iPod Touch that is named after a tampon, has no practical use and is possibly the most pointless gadget in the world, but they all "just LOVE it" and apparently "Macs are the best computers in the World" and "PCs are for plebs and people with no sense of aesthetics" and so on and so on ad infinitum. This is the single most off-putting aspect of Mac ownership, once you buy one, the urge to act all superior and preachy will creep up on you like a virus and you too could become one of the Mac cult elitist, hanging on to every last word that Steve Jobs utters about his latest gadget designed to suck every last penny out of your wallet... You have been warned!
So yes, Macs are good, but so are PCs these days. It all comes down to what you want to use your computer for, if you like playing games, buy a PC, if you want to feel superior to other computer users, have money to burn and like not having to worry about your computer then buy a Mac.