I feel like I've written this a dozen times so I'm just going to summarize -
#1 - 2015 Oklahoma - Bar none, no contest, the loudest. Not even close. 60 minutes of noise.
#2 - 2001 Georgia - Travis Stephens screen pass at end of game to go ahead. Wall of noise that kept getting louder as he ran, felt upper deck sway more than I thought possible. Only time I've ever worried about safety being in the upper deck.
#3 - 2004 Florida - Wilhoit kick. Incredibly loud moment. Not the loudest game, but ending sequence was peak.
I didn't attend Bama 2022 so I can't speak to that one. I would find it hard to believe anything topped 2015 OU though. That crowd was out for blood for four straight hours.