Kamesennin
Kamesennin (Master Roshi) (Jackie Chun) Whatever whoever this guy was once the most powerful fighter in the world. He developed the Kamehameha, and won the Tenkaichi Budoukai #21. He trained Goku and Krillin.
Unfortunatey, he became a perverted old man.. Ohh well I guess living for over 300 years does that to you. Well he is a tough fighter and knows a lot.