[Update: I have posted an article about all the computers I've owned].
Pictured below (in the final year of its existence) is the first computer I ever called my own. Built out of scrap parts my Dad brought home from his office, I managed to build the computer as a 33 Mhz 386, with 2 MB of RAM and a 20 MB hard drive, eventually upgrading it (in stages) to a 66 Mhz 486 with 8 MB of RAM and a 512 MB hard drive!

mmm... SCSI in a PC!
How, you may ask, could a diehard Mac/Apple fanboy start on a 386? Well, it was all about budget, you see. Free is good, especially when you're a little kid with absolutely zero dollars in the bank.
This computer died shortly after this photo was taken, when I was unplugging a connector from the motherboard while the computer was still powered up. Something sparked, I got the largest jolt of my life, and the computer started smoking. Oh well, such is life.
The one thing I really miss about those early days of computing (and using PCs in general ;-) was the physicality and brutality of computing. I would spend about 1/8 of the time using the computer with the lid off, working in the guts. I would constantly upgrade parts inside to make it a lean, mean, computing machine. Heck, I could still draw diagrams of the three different motherboards that were housed inside the case pictured above, and make an accurate diagram of all the components I had installed at one time or another, and how they were connected together.
With the complexity of computers these days, and the miniaturization and virtualization of everything, tinkering is much more limited. But that's just nostalgia talking—I'm kind of glad I haven't shocked myself touching my iMac, iPad or iPhone yet.