All the mundane ghosts Norman talks to on the way to school. The boy may be an outcast among the living, but with the dead, they know he's a great kid and greet him as such.
Also a good Establishing Character Moment for Norman. Even when late for school, he takes the time to greet all the various ghosts in town, and has clearly done this for a while now.
Neil, a fat outcast, finally breaks through to Norman that he considers his communication with the dead neat, and becomes his friend.
The scene where the boys play with Neil's dead dog, and the fact that Neil totally believes Norman even if he can't see what he can.
Neil's joy at being able to somewhat interact and play with Bub again, even though Bub can't fetch the stick or touch Niel at all and Niel has no idea where Bub is or what he's doing, in is rather sweet too. Also while it is a funny rather funny moment, after Neil gets Norman to try and play "fetch" with them the stick bounces off the tree and hits Neil, Norman panics since he's worried about hurting (and possibly losing) his first normal friend. How does Neil respond? He sits up, showing he's fine with the stick in still in his mouth, smiling.
Neil: "I fetched it."
Norman's grandmother telling Norman the reason why she's still around as a ghost: she promised she would always watch after him.
For some reason, the moment where we see the zombies feeling genuine regret for their executing Agatha seemed surprisingly sweet in seeing that these zombies were much more complex than bedeviled undead victims. And the way Norman mentions that they need to break the cycle to end the curse for good, seems very well done.
Courtney, Neil, Mitch and Alvin standing before the mob to defend Norman and the zombies.
Honestly, just Courtney, after having been shown having no patience for Norman at all, being the first one to rush forward and put herself between her little brother and the mob was a perfectly heartwarming moment.
Courtney: Leave him ALONE!
The film's climax, where a deadly supernatural menace is stopped with empathy and understanding.
Culminating with little Agatha resting her head on Norman's shoulder. D'aaawww...
The film's final scene Norman is watching another horror-movie with his grandmother's ghost when his dad comes in and tries to awkwardly adjust to the fact that his dead mother might be in the room with him and tries to communicate through Norman. "...Hi, mom." Then Norman's mom and sister come in as well and we close with the whole family watching the movie.
The little girl in the mob, the same one who launched a flaming teddy bear into town hall, walks up to a zombie after Norman's friends and sister defend him, and she gives the zombie his arm back.