I used to rp most of the usual suspects like ADnD 2nd Ed, and a lot of White Wolf 2nd Ed sourcebooks.
Couple of the more obscure PnP we played on occasion were;
Deadlands: The Weird West 1st Ed - https://en.wikipedia.org/wiki/Deadlands
Spaghetti western with a supernatural/steampunk twist, had a unique gameplay system that used poker chips and playing cards.
Legend of the Five Rings 1st Ed - https://en.wikipedia.org/wiki/Legend_of_the_Five_Rings_Roleplaying_Game
Feudal Japan, only spirits are real and they are super pissed off. Had a cool Iaijutsu duelling system that would often result in instant player death if you fumbled your rolls.