I can’t think of Killing Joke without laughing at just how hard any Barbara Gordon who came after would reflexively kick the $#!+ out of the Joker if she found him on the doorstep. Seriously, can you imagine a Batgirl written by Bruce Timm or Paul Dini or Glenn Murakami or Gail Simone even being dumb enough to just fling the door open in Gotham in the first place?