Heartwarming / The Hanged Man

• David's interactions with Will. When he's called up to bail him out of trouble, he doesn't hesitate in offering to pay for the damages or taking Will home with him. It's even more heartwarming when you learn that David is Will's older half-brother. He doesn't harbor any resentment towards Will, especially since his father left David and his mother.
• Some of Keith's interactions with Will. After Will passes out from seeing a shadow in one of the rooms, he wakes up with Keith's coat draped over him. In the Happy Ending, he manages to save Will twice from Ed.
• The explanation for the note Will is carrying in the True End. David did write it, but it wasn't meant to be a threat. It was a quote from his father's favorite detective show and it was meant to be a form of congratulations. Yes, even though he was left to take care of his elderly mother on his own, David still loved his father and wished the best for him.
• The second playthrough of the Good Ending has a sweet moment with Sophie. After being yelled at by Will telling her to leave earlier, she apparently came back for him anyway. Despite how rocky things have been between them, she still cared about him to bring him back to David.
• The entirety of the Good Ends. After Will is taken to the hospital, he finally talks to David, who tells him that he wants to be a brotherly figure to him. When he's about to leave with his mother, he meets with Sophie, who wants to hang out with him some time, and Keith, who tells him that David wants to go to a baseball game with him in spring. Depending on which Good End you get, he might have found Pop and gives him back to Will.
• In a dark way, Robert's interactions with his brother, Ed. He does everything he can to protect his brother from being convicted for murder, even if he becomes an accomplice. In a few Bad Ends, he tells Ed that he will go to hell with him. He even justifies Ed's murder of their father, saying that his father was a terrible person.