not really sure about the first pc i ever used but the first i built was an amd k6-2 on an aopen ax59 pro with a 64meg stick of pc100 and what i thought was a massive overkill 12.7 gb quantum fireball with a voodoo banshee and assorted other upgrades later on.
voodoo the graphics decelerator 
Toshiba Satellite brick with Win95, one parallel port, one serial port (for the mouse), proprietary connector for the external floppy disk reader/writer, no audio outputs and a slot filled with a modem card to connect it to 56k modem. I remember it not having a trackpad, just a "nipple" in the middle of the keyboard and I liked it a lot (If you want to make a pun out of it it's up to you lol) more than I like trackpad right now. It was an awesome machine and I loved it so much. I remember loading pages during the weekend and seeing a noticable difference in loading times since more people where accessing the web. Also downloading programs and updates required the PC to stay on all night and it would finish usually in the morning. Those were times when I just had fun with a PC, that's it.
The first computer I laid my hands on to my memory was a Windows 98 machine, probably a Compaq, proooobably something like a Pentium III. I was like, 3 years old at the time, so I don't remember that well.
the first computer I actually bought with my own money was a Toshiba Satellite laptop with an AMD E-350. It was a cancerous piece of garbage with horrible QC, but it was mine and I loved it.
the first computer that I actually built on my own without help is the machine I have now - 2600K, Z77 Extreme9 and a 240mm water cooler. Differences now are the case, the PSU and the graphics card.
commodore 64
10 print "my name is gary"
20 goto 10
run
Same here. The massive 20MB hard disk was incredible!

I was too young to remember the name of the actual PC but I do remember playing this game with my sister a bunch so it must have had DOS (this was sometime between 1998-2002)
My first PC was a no cache celeron based system that my dad had bought/built when it was new and then gave to me in the early 2000s. I used that until basically 2008 and then had an Xbox for a few years until I built my first PC with a Phenom II X3 720 BE and some random GT 630.
I had an abit motherboard that had dual celeron p3

For years I had 'dat dual core' experience before everyone else...
Spectrum 48K with a cassette reader/recorder, similar to this:
Ah, those loading noises, the infamous failure to load after 80 laps... Fine-tuning the cassette reader, fine-tuning the TV signal... Spending an afternoon typing a program from a magazine, only to discover 60% of it was creating a font, and that those blank lines weren't there just for clarity...
And then the games. Technology was limited, but creativity was off the roof.
Good times 
First machine was an old att 8086 with dual 5.25 floppy drives and a 20 meg hard drive(added later) that was in one of the isa slots(might have been something else, can't remember). It was a hand me down that I used to play old games.
First new computer was a compaq 486 dx2 66mhz with 8 megs of ram, a 530ish meg hard drive, dual speed cd-rom and a 15 inch crt. The system ran windows 3.11 with tab works on top. At the time the 8 megs of ram was higher end(most had 4) and the 15 inch crt was an upgrade. It also had a 14.4 modem in it. My parents got me prodigy internet which I think gave me 10 hours a month online at first.
First computer I purchased was Atari 800xl. Saved a lot of money doing lawns Mom game me extra money to do house cleaning. Then I saved up and got a non Atari 5.25 floppy that you could daisy chain them together. Those where the days you had to join your local Atari group to acquire software. My next PC was an 8086 8Mhz with twin 5.25 floppy, it was real fun to load AutoCad from floppy all 5 or 6 of them. Those where the days you spent time learning all the ways to get software with no internet.
Thanks for the thread this brings back some great memories.
Would love to get a 800xl that is dead and put a pi in it and run Atari and commodore emulators.
Gorillas! I played that for hours and hours.
The game consists of two gorillas throwing explosive bananas at each other
Sadly, we shall now never see Wendell and Logan re-enact this
... and incredibly loud! lol