First of all, thanks for all your explanations concerning the games I didn't know - there is always something new to learn left
LordBug: Speedball / Speedball 2 might be right, but I just can't agree on Quake. It got far less attention than Doom here and as for being the first 'true' 3D game, I seem to remember some before it. Descent for example. I have to confess I never really followed that genre though.
One genre which is still missing completely is hex-strategy (for the lack of a better term). In the 80s, it was one of the
greatest genres, a huge amount of titles appeared! Some old SSI game would probably be fitting there, but I can't name one at the moment......