I plinked at Linux a bit before this, but I ran various types of Unix over the years before hand and was intrigued about Linux. My job at the time used SCO, Interactive, Kodak, AIX, HP-UX, and a couple other versions. (I think I was up to near 40 different branches at one point...)
https://en.wikipedia.org/wiki/Yggdrasil_Linux/GNU/X
Redhat and Suse turned into more my speed, and then Gentoo, though I went back to less intensive around 2006.