Starting off it's probably Terry Funk, but there is a lot of people sniffing the top. Hansen, Flair, Jumbo, Kawada, Negro Casas, Fujinami, Tenryu, etc...
I like the versatility and the great runs as a babyface and a heel. Great technical, brawls and crazy hardcore stuff. He kept everything interesting, no matter the match. I'm ready to be swayed though.