Linux

Ubuntu around 2006-2007, not sure the exact one I used.

Slackware and then SuSE 7.2, I think it was.

Slackware 3.0, so must have been late 1995 to early/mid 1996. It was included with the book Linux Unleashed, I believe.

I recall having to rebuild the kernel to get sound drivers working (voxware, if I recall). I can't remember if they were included with the kernel, or if I had to patch it. I followed the directions in the book, presumably including updating LILO, and it actually worked. I think that if I broke the kernel, there's a good chance I'd've given up on Linux at that point, so good thing it worked first try!

OpenBSD on the Amiga in 95-96 or so.

My first distro was Manjaro. It was really cool, but also I remember having some trouble getting things to work on it without super extensive troubleshooting.

It was around 2001 and I started by dual booting Windows with Red Hat, don't remember which version. Eventually I dropped Windows and dropped the dual boot and switched from Red Hat to Ubuntu.

Slackware here, and I still use it! Tried several alternatives but I just keep going back.

Mandrake Linux 6.5. At the time I was drawn to it because they had a version that worked with the sims game.

RedHat here in the late 90s, back when you could still find yourself writing a "modeline."

Then Debian in the early 00s when apt was still a major discriminator. Finally, Ubuntu around 2008 just so I was running the same thing I was recommending to family members for ease of use. (At the time, Ubuntu sported the same ease of installation and hardware detection I'd found with Knoppix.)

Now on Xubuntu, but seriously eyeing a return to Debian.

Ubuntu and Kali almost at the same time