I actually cringe when I watch Batman II nowadays. I can't believe the guy who wrote "Heathers", Dan Waters, put in such grotesque dialog for The Penguin. It's plain awful stuff. I liked 40% of Batman II.
For Batman I, I didn't like much of anything after the Joker is on the parade float, it got really silly in that last act. The 1st act kicked butt, but it just lost its way after that.