This is coming from a certified computer technician (both PC's and Mac's):
HANDS DOWN, Mac is better in almost every way when compared to an OEM PC that you get from Best Buy or wherever. OEM PC's come loaded with garbage and the Windows OS has a ton of faults to boot. Combine the two and you've got a piece of shit computer that can barely run. Despite this fact, if you install a blank clean of your OS (this means without all the garbage from HP, Dell, whatever), apply the necessary tweaks to your machine, and install a good AntiVirus, you can get a computer that's just as dependable and reliable as a Mac for a quarter of the price.
What you can't get is the super quality case that comes with a Mac Pro. That's why some people go through all the work to gut a Mac Pro and put a PC inside of it. I've never done it personally, but I'm going to try it one day. You can get a Mac Pro with a blown logic board for $50 on Craigslist if you wait long enough. I have a friend that just got one two days ago and he plans to put his awesome custom built i7 computer in there that has 64gb of memory. The thing cost just as much as a Mac Pro, but he got a computer that's SHITLOADS better and he's now able to get a great case along with it.
Conclusion: Macs are better than PC's when compared to the quality of the case. If you compare them to OEM PC's, they're better in almost every way. BUT with a little time and effort, you can get a decent PC with the same specs as the $3k Mac for less than $800 with a kickass Mac Pro case.
That's just BS. Obviously your knowledge of PC's is severely outdated. Most PC's will last 6-8 years pretty easily without giving you too much trouble. Just stick away from Emachines and Gateway and you'll be fine.