Nolan on Burton's Penguin:
Crave Online: Do you think you could ever push it too far with a franchise like this?
Christopher Nolan: Well, you certainly can push it too far, but interestingly there are different ways to be disturbing. I mean, I don't talk a lot about the previous films because I didn’t make them and they're not mine to talk about. But certainly if you look at Batman Returns with Danny DeVito as The Penguin, eating the fish and everything, there are some extraordinarily disturbing images in that movie. But they're coming it at from a surreal point of view.
I also remember Nolan saying in an interview that Burton's Penguin was the best version of the character, but I can't find the article where he said that online.