I had completely forgotten about Gable.
Spitz in Munich immediately came to mind though, but then I'm from Bloomington so he's a hometown favourite.
And with cycling being so popular in B'town I'll segue into...
Eddy Merckx in the 1969 Tour de France. He not only won the Yellow Jersey, but also the Green Jersey (Points Classification) and the Polka-Dot Jersey (King of the Mountains) - this feat has never been duplicated in the Tour de France. He also won six individual stages, including a mountain stage by a staggering 8 minutes after riding alone for over 140km. Merckx held the Yellow jersey from stage 6 all the way to the finish in Paris. His overall margin of victory at the end of the 22 stage race was 17 minutes and 54 seconds - the largest winning margin in Tour de France history. This was also his first Tour de France and the first of his five overall wins.
Even now, knowing the history and Merckx's impressive list of wins and records this stands far above anything else he or any other cyclist has done.