Obscure games from worst to ones that are actually playable ...
World of Synnibar
Cadillacs & Dinosaurs
Own all, except Living Steel which was was soo bad I refused. Of the bunch, the only one really worth playing was Providence. Cadillac & Dinsoaurs is a perfect example for the "Why things from one medium is not transferable to another". Great Setting to read about, bad setting to play in.
HarnMaster is a great game that is written in a pretentious style that makes the game more difficult than it really needs to be. For CP
1st ed by Herbie Brennan (1982) Yaquinto (was a big dice company back in the day).
A time-travel RPG. Characters travel back in time using "Personal Energy" which limits how much they can bring with them. The system is simple and loose, to encourage wild action.
It was bad, even when compared to the RPGs of the era. You technically were playing yourself... but not really. To start the game, THE RULES STATED (roughly), "To have a darkened room with all the players sitting around a table holding hands. Light a candle in the center. Have the group chant "the travel mantra" to send yourself to these other times. "
Needless to say, for a variety of reasons, the game did not catch on. For others:
Runebearer is not that obscure. While it is not the official game of the internet, Runebearer/ Bostonia is quite the popular game. Go Chris!
Now if you want obscure:
1st ed by Andrew LaRoy (1997) Studio Cranium
An multigenre anime-based RPG. The system uses d20 for resolution and d6 for damage and other effects. The main rulebook (103 pages) includes several campaign settings: including police in a modern-day magic world, a space opera campaign, and friendly competition of ace pilots from all sides after WWII.