I only recommend PCs to people who have the technical mojo to handle building and troubleshooting them. What's funny is that implies that about 95% of people should use Macs with only a tiny percentage using PCs.
I would love it if you could just buy Mac-compatible motherboards, processors, power supplies and so on at NewEgg. On the other hand, it would take away a lot of the Mac's advantages - having to support hundreds of motherboards made by dozens of different companies can be difficult. Apple has it easy - they make the hardware, and they write the software. It's just a different philosophy. I'd still like to build a completely tricked out Mac system from NewEgg parts if I could.
Rather than continuing to explain the subject of how tricked out PCs can get, I'll simply show you a picture of a case that you can buy if you really want:
No, my computer does not look like that. It's very plain, kind of a bronze-grey color.