Tear Jerker / Superman & Batman: Generations

• Joel Kent's entire life. He was born without powers because he was prenatally exposed to Gold Kryptonite, he was led astray when the Ultra-Humanite (the one who de-powered him in the first place) convinced him that his father Superman deliberately made him powerless and becomes an Unwitting Pawn for the Ultra-Humanite's schemes when he is manipulated into killing his own sister Supergirl after obtaining a serum that gives him Kryptonian powers, only to then learn the serum is fatal and to die while the Ultra-Humanite gloats to his face that he deceived him all along.
• As collateral damage of Kara's demise, her brother killed her shortly after she married Bruce Wayne, Jr., and Bruce, Jr. didn't take becoming a widower well at all, to the point that he went down a path of becoming more jaded and ruthless until the other heroes call him out for almost killing Alan Scott.
• If you thought the usual circumstances of Bruce Wayne being orphaned were tragic enough, Generations II reveals that Jonathan Kent saw the murders of Thomas and Martha Wayne happen on the Chronoscope and tried to warn the Waynes, but Thomas and Martha did nothing and willingly let their deaths occur, feeling that their lives are a necessary price to pay for their son growing up to become Gotham City's defender.
• Ultra-Humanite getting under Superman's skin by gloating that he had murdered Jimmy Olsen, Lucy, their son Clark, Clark Olsen's own wife and children and Perry White, Jr. while the Man of Steel was away.
• Dick Grayson's death at the Joker's hands, and how it results in Grayson becoming a vengeful spirit desiring revenge against the Joker even if he risks damning himself.