2. Batman: Hush
Batman: Hush was written by Jeph Loeb and drawn by Jim Lee. The storyline ran through the Batman monthly series, from December 2002 to September 2003. It features a mysterious villain called Hush, who attempts to sabotage Batman from afar while utilising a number of the Bat's rogues gallery, including The Joker, Harley Quinn, The Riddler, Two-Face, Talia and Ra's al Ghul, Poison Ivy, and Clayface. Throughout the story we also see a number of other characters, including Superman, Oracle, Killer Croc, Robin, Huntress, Nightwing, and Catwoman. Batman's investigation into Hush's plot takes him on a long saga through Gotham City, as it continues evolving and expanding around him. His romantic relationship with Selina Kyle is featured predominantly, and as Bruce gets more tangled in Hush's scheme, we see glimpses into his past that make the investigation incredibly personal. It's one of the most exciting mysteries we've seen Batman face in his history, and the exceptional wealth of character cameos and intricate story lines would make it a fun and fascinating animated feature.