I learned to Hack on a Commodore PET that was owned by my elementary school. It was far more fun to modify the learning programs we were supposed to be using, than to actually USE the programs as intended.

Then the school got a Commodore 64. Oooh! Colors!

Then the first PC that was mine, and located at my house was a PCjr (but I had the "real" keyboard). A lot of people slam the jr, and I've never understood why. I wrote thousands of lines of BASIC on it, learned to interface with various peripherals, hand-soldered a memory expansion card, and other fun things.

Then I built an IBM PC from parts (and by PC I mean a 5150), followed shortly by an XT, and then about a year later an AT (and I overclocked it from 6Mhz to 8Mhz, IIRC).

Next was a PS/2 Model 30 (bought), Model 55 (built), Thinkpad 700 (built), and a couple of other IBM machines. If it's not obvious by now, my dad worked for IBM, so I had access to a lot of IBM parts. The PS/2 Model 30 talked to the AT and jr over a parallel-port LANtastic network. Then I got actual LANtastic ISA cards. There was PCNet broadband network in there somewhere also.

After the IBM's was a whole slew of built clones, from a 486sx, up through Pentiums.