Sorry, voice of dissent here. Most of the positive attributes to a mac are marketing oriented and IMO not based in fact...at least since Windows XP came out.
I've had both, the mac bought for my wife because she wanted to try it out.
We saw no practical difference between the mac and a windows XP pc in usability, maintenance or reliability. In fact, the mac blew two hard drives over 3 years because they werent adequately cooled. The hardware in the far more expensive mac was no different from a decent budget PC.
While its possible to run both windows and macosx on the newer macs, theres a small amount of technical complexity, and you may have to buy both OS's.
As far as "virus problems" on the PC, I have a scanner that came with the PC, it self updates, I've never been infected with a virus on it or had any problems with the scanner. If I took the 'tray icon' away, I'd never even know it was there. There is absolutely nothing special about a mac that protects it from spam. Many security experts are not pleased with the number of open exploits in the mac os and apple seems pretty lax in fixing some of them. So, its not that the mac is virus proof in any way...its just that nobody has bothered to write a virus to attack a small market share machine.
Most modern XP/Vista machines have everything you need in the box, work right out of the box, work with every application thats not mac specific (which is not many), connect to peripherals and the internet every bit as well if not better, and costs 20-50% less for the same product quality and performance points.
The bottom line on our mac experience is that it was a fine machine with a well working set of software, but that we spent extra money on purported benefits that really didnt materialize.
That having been said, and without trying to upset anyone (really), the mac is a "destination product" that, due to great marketing, people want to buy because there is a strong suggestion that it will change their image, make their lives better, solve problems, make them look more affluent or make them more attractive to the opposite sex.
The Apple/Mac marketing campaign has been geared up to make the buyer feel that the purchase will make them feel more creative, young, intelligent, artistic, cool and gosh, it'll be easy to use and solve all your computing problems.
Here's a different spin:
http://www.internet-nexus.com/2007/01/im-mac-im-pc.htm
One thing my wife liked a lot was the colors, although that led to the purchase of some new peripherals to match the color of the computer. Yay, even more money spent...
All that having been said, you wont screw up by buying a mac. It'll work great for you.
Just be prepared for a bit of disappointment. And you'll soon discover that almost everything is done for the PC first, then belatedly for the mac. So you might have to wait for an application to come out for the mac, you may find directions on using a product or service on the mac to be somewhat inadequate or not as well fleshed out, and you may find that tech support folks are far more knowledgeable about their product on the PC than on the Mac.