Harley Quinn: Our Worlds at War #1

Part of DC's 2001 "Our Worlds at War" crossover event, this one-shot puts Harley Quinn front and center in a way that's hard to ignore. Jae Lee's cover depicts a battered, wide-eyed Harley — spattered in red, her jester costume torn — screaming as a sleek jet aircraft streaks past behind her, the tagline "The Last, Best Hope?" hanging provocatively beneath her. With a stellar interior creative roster including Karl Kesel, Amanda Conner, Paul Chadwick, and Paul Grist, this "Casualties of War" tie-in makes a compelling case that even Gotham's wildest wildcard has a role to play when the entire DC universe is on the line.