I'm not so much a hobbyist as reminiscing about my youth. I am a firm believer in the KISS principle (Keep It Simple, Stupid!) and dislike the bloated OS's we have today, even many Linux distributions. While my system hasn't booted in nearly 10 years (likely due to the age of the 680x0 motherboard), Amiga is still my favorite OS. I've wanted a PPC OS4 system for years but keep postponing the purchase.
There were so many oddball computer systems back then: Timex-Sinclair, SpectraVideo, the Intellivision computer, the Coleco Adam, that import from Japan whose name I can't remember. I expect it keeps you busy.