Bobby Fischer..FTW! Virtually self-taught. Hardly ever had teachers because he became the strongest chess player in the US when he was barely a teenager. he took on the Russian giant with her army of grandmasters...and he stood alone.
sure, he had issues. deep, psychological and personality issues, but that was the side effect of being isolated from the world and having his own world. for Bobby, chess was life and life was chess. You can say he become one dimensional...but in chess, he was king.