re: What's the most famous play in lsu football history? EDITED TO ADD JUST FOOTBALL

Believe it or not, at least among older fans this play involving YA Tittle is a pretty famous LSU play, too:

In Tittle's day of iron man football, he played on both offense and defense. While on defense during a 20–18 loss to SEC champion Ole Miss in his senior season, Tittle's belt buckle was torn off as he intercepted a pass from Charlie Conerly and broke a tackle. He ran down the sideline with one arm cradling the ball and the other holding up his pants. At the Ole Miss 20-yard line, as he attempted to stiff-arm a defender, Tittle's pants fell and he tripped and fell onto his face. The fall kept him from scoring the game-winning touchdown.[11][12]