I build my own for use at home. I've done some computer repair, but I'm a software guy. When I build a computer I usually go for the cheapest, most efficient stuff. Not into all of that flashy **** that people whack off over, but offers barely any advantage. Lots of doofuses are into computers and think the latest parts with the highest numbers are always the things to buy, and they waste their money on them. Kind of like people who watch movies just for the explosions. Viny's probably one of these people. Hack.
I've always used really old computers and parts to do what I need to do. My work laptop that I use 6-8 hours a day and make my living off of is a single-core, 1.8 Ghz dinosaur. Still runs great, though. I just barely upgraded my desktop to run Windows 7, after using a desktop that was on par with the speed of my laptop for about 5 years.
Never got into Macs though. Kind of always felt like they were the oxy-moron of computers. More expensive, better written OS, but less support and not the standard. They're also horribly gimmicky.. I'm not sure I'd feel okay owning one and contributing my money to their trendy advertising campaigns.