hi
if looking for the best in the world then i think leadbetter's teaching school, also Plez teaching school, Bob Torrance would be another that came to mind.
AG Bonner and Dalton Mccray for the shear number of tapes and videos they have sold and had the huge number of people that used there tapes and DVD.s
also Ben Hogan for his book that is still one of the most read instruction books ever read.
cheers
bill