I've been thinking about some Batman story lines that have not been outlined in Post- original Crisis that could be interesting (if they have not been done).

Deadshot's first appearance and how he ends up in jail the first time. Englehart/Rogers Batman books reset the character with the uniform and that he had been in jail for quite a few years. I know that Deadshot was a golden age villain, but I don't think that story has been told in a early Batman: Year One style.

Calendar Man is a big part of The Long Halloween, but the story on how he ends up in Arkham for that storyline I don't think has been told (or at least I have not read it).