Year Two. The story where Batman was forced to work with Joe Chill and is the most under rated story.
There’s so many. In cannon, I’d start with Year One, then Zero Year to see the take on his origin. Long Halloween, Dark Knight Returns, Killing Joke, Knightfall, Court Of Owls, Endgame, No Man’s Land, Hush. Death In The Family( available in DC Universe ) Hush. That should get you started🍀