3. Dustin Johnson, 2010 PGA Championship

Dustin Johnson hits from a bunker on the 18th hole at Whistling Straits during the final round of the 2010 PGA Championship. (Photo: Getty Images)

On the final hole at Whistling Straits, Johnson’s drive sailed right into a patch of sand. Players had been warned that all sandy areas would be treated as bunkers. Nevertheless, Johnson grounded his club in what was deemed to be such an area before his second shot, leading to a two-stroke penalty. It knocked him out of a playoff with Martin Kaymer and Bubba Watson (which Kaymer ultimately won). Interestingly, it wasn’t even Johnson’s biggest Rules controversy of the decade.