Nagato. He was taught by Jiraiya during the 2nd shinobi world war and I'm not even sure if Minato had been born yet at that point. He most likely was but I doubt he was that old.
Nagato was who Jiraiya's first book was based on The Tale of the Utterly Gutsy Shinobi in the book the character's name was Naruto and he had the Rinnegan later on Minato would name his unborn son after the stories' protaganist...