Batman has beaten the crap out of the Joker so many times I don't know how he can even have any teeth left. But this issue the Clown prince of crime has to receive his most well-deserved beating. Scarecrow gets a big surprise when his gas causes Batman to see something that only gets him madder. And Joker gets the worst of it. The only down side is the bad guys get away.
I find it fitting that Jim Aparo got to do this one as he also drew the story where poor Jason died. Who better to draw Batman avenging him than the same artist? This is my favorite chapter in the Knightfall saga. I remember reading it over and over when I first bought it way back when.