I own both.. I had enough money to make the choice but you may not.. I got a mac because the creative industry tends to use macs.. I think the PC is 100% capable of everything that mac does but the fact remains that the industry (music, film, etc.) uses apple computers and apple software..I'm a film major and HAD to get a mac.. Don't get me wrong, Adobe Premiere is easy and works but the industry laughs at premiere.. They embraced final cut pro and, since I want to be part of that industry, should know how to use FCP... Same thing goes with the music, art world.. Every serious graphic designer that I know uses a mac even though photoshop has long been available for the PC.. Yes, a mac will cost you a lot more but it's really a niche item in my opinion - professionals that have the money buy macs.. Luckily, my lovely G4 works great for everyday tasks too... But I still enjoy the freedom that my PC offers (you can't game on a mac, P2P's suck on the mac, etc.etc. etc.).. Those thinks are not weaknesses of the mac- it's just made for a different market that doesn't play game or download mp3s..
I'm adding some of the negatives about my mac.. Just to be fair:
-Kinda slow sometimes.. I haven't pinned down the exact reason but it's getting annoying
-You can't upgrade the thing! I've added ram, a bigger hd , etc. (uses standard pc equipmet) but that's the entire upgrade process.. The new g5 is out but I can't just pop in a new CPU or get a new mother board..
-Lack of software.. Every major application is available for it (office, etc. etc.) and the included software (iphoto, etc.) rocks harder than most commercial pc software, but the choice is pretty limited.. It doesn't bother me at all but it may bother you..
-Expensive.. But, again, i feel that it's a niche item.. The iMac line should be cheaper but the G5s price premium is because it's not a "surf the net/email" box..
-horrible warranty! by the extended warranty!!!! I didn't and now I'm seriously screwed...
That's about it.. I use my pc about 99% of the time.. I prefer my pc and can not justify the expense of the mac if it wasn't for FCP and the industries dependance on the mac..Snobby, yes, but you can't expect an industry to change - you just have to use the same tools that they do..