Eh, personally I've never really liked the Joker that much. He's just too extra for my tastes. When he's trying to espouse some kind of philosophy, it's riddled with bullshit, and when he's not, he's just "tee hee, killing and being crazy is FUN!" And I have very little patience for that. Though, frankly, I have almost zero tolerance for mental disorders as super powers/personas in comic books in the first place. Him and Harley Quinn, and the fanbase's obsessive love of them, just bothers me on so many levels. I much prefer far more mentally fucking stable villains, who can articulate an actual ethos, and world view, that isn't founded in batshittery and chemical imbalance.
It's actually kind of depressing how many villains in comics, Batman especially, are basically just mental case studies, given a cheesy gimmick and a name, and just tossed out into Gotham to do shit. At least villains like Mr. Freeze (from the cartoon at least), have a motivation that you can at least understand, if not condone.