Easy for me.
First was the Outlaws in 1979. Green Grass and High Tides for about 28 minutes and ear piercing volumes. Ears rang for two solid days.
Second was Ian Hunter with Mick Ronson on guitar. I was on the rail and it was another ear piercing experience. Deafening.
Third, being under the stack in 1989 at Autzen Stadium for the Dead and during drums Mickey’s bar thing was reverberating crazily. Could feel it in my chest. That was tough.
Honorable mention, any electric Jack White show. Frankly, Just doesn’t need to be that loud.
I have had tinnitus ever since the 1980’s and now wearing aides. Paying the price.