Thinking about it I've also played a lot of RPGs that I don't know if they would count as obscure but like... I never see people on this forum talk about them.

Stuff like Fallout 1&2, Elder Scrolls I & II (Arena & Daggerfall), Planescape Torment etc.

Zork isn't an RPG, is it? That game is great. I guess it's more of like... a text based adventure game.