The ending of chapter 4 when Sarah says goodbye to Max and gives him some much needed affirmation (though that doesn't stop it from being creepy at the same time).
Morgan's Last Game. Olmec, Grimwall and Sarah encouraging and saying goodbye to Max.
Sarah: "You're my hero. I love you."
Max being reunited with his wife at the end of the game, plus the picture that's seen during the end credits.
In chapter four, Max is transported into a Circus of Fear, where he's turned into his dead little sister Sarah. He eventually finds his way to a haunted house, where he is confronted by ghosts of himself and his family. After correcting his greatest failure (not being able to find his sister's favorite toy), he finally gives it to her. Suddenly, Max is back to normal, Sarah's ghost is fully formed, and her sepia-tone room becomes bright and vibrant as Max finally gets over his grief and hugs her.
The two cutscenes where Sara interacts with Spanky the Clown are cute, albeit odd. Sara whispering "thank you" at the end only adds to the charm.