I've done my best to try to find and play the most obscure of RPG games, and I think one of the most obscure I've ever played has been Amulets and Armor.
It sold literally no copies on release more then a few decades ago, and the only thing that rose awareness of this game was a co-operative let's play of it back in 2012.
If you wanted to play the child of Doom and Daggerfall, along with a buddy or two, it's pretty decent! It's a dos game though, so I'd make sure you have DOSbox ready for it.
Look up a website for some info on it's systems and if you want class advice, Necromancer and Paladin are some of the better classes to play, because they are the least restrictive.