Arnold Palmer vs. Jack Nicklaus
The 1960 U.S. Open was the King's crowning moment, with a final-round 65 to win. But Ben Hogan declared, "I played with a kid today who should have won this thing by 10 shots" referring to Jack Nicklaus. Two years later, Nicklaus took the title in Arnold's Western Pennsylvania backyard. It was working class vs. privilege, draw vs. fade, matinee idol vs. heavy, crew-cut kid. The rivalry evolved into a feud until the 1990s; now there's a genuine friendship.