Another thing I forgot to add about Jack's Joker is that he doesn't feel as if he is Batman's greatest foe in Burton's film. He just felt like another villain. The Joker is supposed to be the villain that causes so much crap happening to Batman (mentally torturing him in a way). Other than him killing Batman's parents, he didn't affect Batman that much. Once again, this is Burton's fault and not Jack's.
His origin is also done poorly. When he was Jack Napier, he was one person. And after he falls in the vat of chemicals and resurfaces, he is the exact same person that he was before except that he laughs more. To me, that is just bad writing.
other than killing his parents? thats a pretty big other than dont you think i mean the death of his parents is what made him batman without that he would be a drastically diffrent person
i agree about the chemical vat not changing him enough
In comics, a superhero's arch-enemy is supposed to be one of the biggest challenges that the hero ever faced. During the film, the Joker didn't feel as one of the toughest challenges that Batman would have to face in his entire career. In the movie, he didn't feel as if he was one of the biggest threats to Gotham (which is how the Joker is mostly seen as). As for him killling his parents, that took place before he became the Joker (when he was supposedly "normal" despite him not changing after the chemical vat incident).
As Jack Napier, he was your typical run-of-the-mill gangster, maybe he had a little more of a screw loose than most, but overall, he was mostly interested in inheriting Grissom's empire and stealing his girl.
As the Joker, this guy just loved killing and being the star of the show. Being #1, being the guy in the headlines, being better than Batman. That was one of the plot points in their film. Joker kept trying to "1 up" Batman. Remember when he complained Batman was stealing his press?