I thought Jack was like a mix of all eras of Joker up to that point (late 80s). There's a bit of Cesar Romero, a bit of the early 1940s mobster Joker, and some of the more darker Joker from comics like The Killing Joke. And of course, a bit of Jack Nicholson's own style thrown in there. I still think, the 1989 movie gives us way more iconic Joker moments.. like the "Mirror, Mirror!" scene, the first reveal, the final confrontation, etc.. way more memorable lines too. Jack didn't have the physicality of Heath, but he has way more acting talent. He really commands the screen. While Ledger had a great method style of acting, he didn't have the same charisma as Jack. I can still watch Jack's performances over and over, while Ledger's just don't have the same re-watchability factor. There are only a few scenes I like of his Joker. If he had as many iconic and memorable scenes as Jack, then he would've been the best Joker ever.