OK, I'll join in, just for fun, even though I don't really upgrade/replace my computers very often.
The very first computer I remember having at home was a DEC PC that my Dad brought home from work so he could do extra work at home in the early 80's. I'm not sure the model but I think it was a DEC Rainbow 100 as that's about the right time frame and it looks pretty similar to what I remember.
The first one I actually used was a lovely TI-99/4A. Still have it in a box on a shelf, in fact. Ah, the fond memories of waiting for the next
Electronic Fun with Computers & Games magazine to show up so we could find the new programs, spend hours typing them in, saving them on magnetic audio tape, and then have them not work...
Played lots of games on the 8086 clone that was the family computer for a really long time (anyone else remember the TURBO button?). I think it was upgraded to a 386 and eventually to a Pentium 60 in the mid 90's, but I wasn't at home at that point.
I started running the original Seti@Home project somewhere around 2000, so I guess my first personal cruncher would have been the Cyrix 686 that I had at the time, plus a room full of crappy old Pentium 133 and 166 machines at work that just sat there doing nothing most of the time so I (with permission) gave them something to do at night.

Had to learn how to sneaker-net since none of them had Internet access.
Replaced that 686 with an AMD Sempron 2500+ some time around 2005 and overclocked the crap out of the thing. It lasted quite a long time, all things considered, eventually replaced with a Dell with a Core2Duo (don't recall which) that I got for free from my wife's work around 2010.
Went through a few other 2nd hand work machines until I bought an AMAZING new gaming machine from Dell's outlet store with an i5-4570, a 'hybrid' SSD drive (that sucked) and an ATI HD 5670 somewhere around 2015. Swapped the i5 out for an i7 and the HD 5670 for a GTX 1060 a couple of years ago and that blazing fast monster was my main system up until April of 2020 when I finally entered the real world of computing.
Current main system is a Ryzen 9 3900X, 32 GB of 3600Mhz CL16 RAM, multiple SSDs for OS and storage, and the GTX 1060, and an R9 280X with a death wish. Gonna retire the 280X soon as I can't keep it from constantly overheating, and will replace the 1060 when I find something worthy at a not insane price.