Batman: The Dark Knight Returns

A retired and world-weary Bruce Wayne returns to his mantle as Batman to clean up Gotham City which has been overrun by crime and violence in his 10-year absence. Along with his arch-nemesis, the Joker and corrupt officials, scores of gangs have taken over including some who call themselves, the Sons of Batman. Batman straightens out the city, but the corrupt government wants Batman eliminated. Using Superman as his pawn, the general orders him to take out the Batman. Knowing he must face the Man of Steel, Batman arms himself with a special suit and gets help from the new Robin and Green Arrow. Surprisingly, Batman defeats Superman, but dies of a heart attack at the end of the battle. His secret identity is finally revealed to the world, but the mystery of how he did it all and where his assets went remains. At the funeral, Superman picks up a faint heartbeat in Wayne's coffin and gives Robin a knowing wink before he walks away.