I have both a Mac OS-X(panther) PC and a Win XP-Pro PC. So I am going to speak on the subject , like it or not.
VIRUS: The modern computer virus is usually like the pimple on your back you never even knew you had. Yes, Mac computers get fewer of them (if any, I'm not sure) but the few I got on my XP computer did no noticable damage to anything. I thought everything was fine until Antivirus said otherwise and fixed the problem easily.
In short: Virus's are not even the common cold and everybody fears them like cancerous-Aids. Less than 1% of PC's are the actual targets of these viruses, normally servers and huge corporations, but every buyer of a Wal*Mart Emachine thinks heathen commiee "Hackers" are out to use their POS 'net-surfing boxes to launch missle attac ks against the pentagon.
GAMES: Yeah, windows has more, better games. Mac owners have to deal with it. If you own a Mac I hope you like Myst. My friend did some sort of voodoo magic and was actually able to make Return to Castle Wolfenstein (for PC) run on a Mac. I don't know the specifics, so I can't tell you what to do.
UPGRADE: Uprgading is the trump card that Windows users love to strap to their groins and dance around Mac user with. Of course the 'powermac' line of computers is as disectable as a regular tower PC. You can't upgrade the iMac or the eMac's processor or video-graphics cards. You can upgrade RAM (with an easy-to reach port for the outside!) easily enough. Of course I could post the genius arguement that less than 1% of windows user could change or even identify a graphics card, but I won't stoop so low.
You can overclock a Mac regardless of popular myth. And the physical structure of an iMac/eMac is designed so auxialliary devices can be "easily" plugged into numerous slots (The eMacs are even on the easy to reach side, not the back).
SOFTWARE: Software is the grand-poobah of the Mac (Unless you belong to the Holy Church of iPod worship). GarageBand, iDVD, iMovie, and iTunes are among the short list of easiest to use/genius consumer level programs ever to grace a computer. iTunes, with its built in download store was made available to PC users so that even more iPods could be sold. (And some say covert PC users to Macs). In that regard iTunes was really a trojan horse, get hooked on the one-click usablity and suddenly you find yourself at the Apple store demoing iDVD and buying an iMac. GarageBand and iMovie are software that you would have to spend, literally, thousands extra to get a similar perfoming PC.
In addition to that Macs have become the de-facto standard for video editing and music production (on a non-platform specific computer). many production companies have actually "downgraded" the pure number crunching supercomputers because one producer can create more finished video material quicker on the "slower" on the Mac. Rumor has it Williams st. Productions (Aqua Teen Hunger Force, Sealab 2021) replaced a $100,000 AVID computer with a $2500 eMac for finished production.
iPod: Love it or hate it, the iPod is likely to do more for the recorded music industry than SACD or DVD-A in the next five years. It is the most popular portable music device since the SONY tape Walkman, and with nearly 100,000,000 songs sold in just a year (Come on, say it in a Dr.Evil voice "One hundred meeeeelion"
)it quickly outpaced the CD-single and may actually be giving the standard-CD a run for its money! (Can someone get any info on download vs.album sale numbers for specific titles?) Plus it can be used in one hand with just a thumb!
COMPUTER DESIGN: I'm not a huge fan of ghostly white, but Apple got it all over Windows in design of the physical device itself. smooth edges, recessed speakers, DVD-drawer button the keyboard, one piece design, weird layered paint-clearcoat/plastic shell,
Titanium laptops.
By being the sole maker of the computers, Apple hands down can build a nicer product (no competition rushing cheap **** to market). Yes this makes the computer cost more, but the design is a huge selling point.
I believe the only comparable designer/builder of a PC would be Alienware.