For me it's that scene in Poltergeist where Carolanne's spirit runs down the stairs through the mom and she can smell her. The way she holds up her scarf and says "that's my baby" hits me the most. I hate kids and I have no instinct to mother, but something about that part literally never fails to make me tear up. JoBeth Williams was flawless in this movie.
https://youtu.be/FXDdGan2kdQ?si=sR0pZ52pzN_j_zOo