Mad Hatter for me. He deserves more love than he gets.
It has to be Mr. Freeze. He was nearly forgotten and C list before Heart of Ice. And now he’s considered one of the classics.
I liked how BTAS Two-Face was a good friend with Bruce Wayne. It made his transformation more tragic as we got to see how much of a good person he used to be. Then Bruce did things to get the old Harv back like when he paid for Two-Face’s surgery. However, because all his attempts were unsuccessful you couldn’t help but feel bad that they never were going to be friends like they used to be.