One scene that never fails to choke me up a bit comes at the end of DS9's "The Visitor." An elderly Jake has dedicated his life to trying to bring his father back from the timeless realm from which he has periodically, and inadvertantly, haunted his son throughout his life. Jake has, in point of fact, ruined his life trying to save his father -- his career as a novelist abandoned, his marriage destroyed, he lives alone, and he has no family or friends anymore.
Sisko is brought back into his son's life one last time. Jake's apparent age is at least his eighties; given how humans age in Trek, he's probably closer to 120 or some such. He is asleep. Sisko is sitting there, looking at him, love in his eye, the way he might have when Jake was a little boy.
But when Jake wakes up, Sisko realizes that Jake has ruined his life for his sake. And then he realizes that Jake intends to kill himself, which will have the effect of flinging Sisko back in time to the instant of the accident -- or so Jake hopes. Sisko is crying, trying to get his son to stop it. "I would never have asked you..."
It's such a heart wrenching moment -- especially for a character, Jake, that DS9 often underserved. It's beautiful and painful, especially for those of us in the audience who recognize how complicated and painful relationships with one's parents can be.
This isn't a movie-but I won't nitpick 'cause it tears me apart every time I see it. And in keeping with your individual take on the theme-The ending of the Inner Light-as soon as his old friend and wife re-appear I start leaking around the edges and it doesn't stop 'till the credits roll.