Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Torchwood
"Out of Time", when John Ellis breaks down upon meeting his now aged and senile son, and Jack comforts John as he commits suicide and when Diane leaves.
"Captain Jack Harkness": the saluting scene and shortly beforehand the kiss. The desperate look in Real!Jack's eyes. And the dance. Oh, the dance. The spotlight shining down on both of them, and everyone else stops dancing, just to watch. It was beautiful and heartbreaking at the same time, since we know what happens the next day. Unfortunately, it's quite possible that Real!Jack, having outed himself so spectacularly, was killed by his own troops.
'Tell my family...I love them' written by Toshiko in her own blood in case she doesn't come back.
"Remember me as I am. Remember Beth."
"Cyberwoman". Watching Ianto's single-minded obsession with keeping Lisa alive, all in the vain hope that somewhere, beneath that cold, monstrous cyber programming is some shred of the woman he fell in love with... Dear God....
Lisa: Hold me, Ianto. I need you to hold me. I need you to tell me it's all right.
And as justified as Jack was in killing Lisa, he knows that Ianto is equally justified for hating him for it.
The "You're my brave, handsome hero" scene with Toshiko sitting on the bed in "To the Last Man".
"Adrift" Gwen reunites a mother with her time-displaced son, who has (unbeknownst to Gwen) gone insane and the mother can't handle it and ends up rejecting him, even though he still loves her.
A little clarification: a mother loses a little boy, and when she gets him back, he's a horribly disfigured middle-aged man. In spite of this, she still loves him and wants to take him home with her...until she learns that he's been driven mad by his experience in the rift, and screams for twenty hours every day.
The boy's mother packing up his belongings at the end of the episode.
Gwen: I thought you wanted to know what happened to him.
Nikki: I did. I was wrong. It was better when I didn't know. Before you, I had hope.
"Adam" the final scene is tear inducing, as Jack opens up the mystery box at the end of the episode and finds it full of sand from the beach where he grew up. And because of the events of the episode, he has no idea what it is or its significance.
When Jack passes out the memory pills to his team..
Tosh: Knowing there has to be more to life than this. Knowing I'm special. Waiting for someone to see it.
Jack: *smiles* I saw it.
All of "Exit Wounds". Just pick a scene.
When Captain John Hart tells Jack, "I am sorry for your losses." Then he kisses Jack on the cheek and leaves. This man is a heartless, deceitful person, and yet he genuinely shows sympathy (or is it empathy?) for the man he claims to love. It's just so damn sweet.
Toshiko's final message to the team.
Okay. So if you're seeing this I guess it means I'm well, dead. I hope it was impressive, not crossing the road or an incident with a toaster. I just wanted to say, it's okay. It really is. Jack, you saved me. You showed me all the wonders of the universe and all those possibilities and I wouldn't have missed it for the world. Thank you. And Owen...you never knew. I love you, all of you. And I hope I did good.
The worst part about that being how she uses it to finally address Owen and give him her declaration of love. Only Owen's not there anymore, either...
Even before that, with Toshiko's plea for Owen to stop shouting because "You're breaking my heart".
The episode's final dialogue—the "calm after the storm" moment when you realize just how much the events of the episode have cost the team:
Jack: Now we carry on.
Gwen: I don't think I can. Not after this.
Jack: You can. We all can. The end is where we start from.
(Fadeout on Jack, holding the remaining members of his team close.)
Children of Earth. God, where to start? Okay, Ianto's death's probably a good starter.
The moment when Jack realizes the consequences of the 456's response to his ultimatium and blurts, "Then I take it back, all right? I take it all back, but not him!"
Ianto: Don't forget me.
Jack: Never could.
Ianto: In a thousand years time, you won't remember me.
What makes it even more tragic is that fact that Jack has the ability to revive the recently deceased. We've seen him do it before—on Ianto. But this time, as Jack leans down to try to breathe life into Ianto's lifeless body, he's already dying himself and just doesn't have the energy, and collapses. God.
And in three seasons of Torchwood and several of Doctor Who, after being buried alive, tortured by the Master for a year, having the little brother he lost return only to cause destruction and the deaths of two of his friends, this is the only time we've ever seen Jack beg—to not lose Ianto.Sniff.
Then there's the moment when Gwen pulls down the sheet covering Ianto's body and adjusts his tie, just slightly. Apparently this was the moment which set the cast members off, too.
The realization that Jack was once partially responsible for the sacrifice of twelve innocent children.
"John Frobisher was a good man."
The scene where Frobisher, after realizing that his daughters will be handed over to the 456, goes into his daughters' room and kills his family and then himself. Horrifying and heartbreaking. Made even worse in retrospect by the fact that the 456 are stopped, so Frobisher killed them allfor nothing.
The climax: Jack destroys the 456 by killing his own grandson in front of his screaming daughter. And he makes himself watch..
The end: absolutely heartbroken, Jack leaves Earth, ostensibly forever.
The scene where the government discuss which children to give to the 456.
The scenes with Ianto's sister and the children, and when Gwen and Rhys are trying to escape with them.
Any scene where civilians fight the soldiers—when the soldiers start taking the children from their homes, when Steven is taken from Alice, when the neighborhood men, led by Ianto's brother-in-law, storm the riot police with rocks and clubs, when PC Andy takes off his vest and jumps into the fray. The series gets darker and sadder with each episode, but the final half-hour of episode 5 is surely some of the most heartwrenching TV every produced.
Every single scene where Gwen was involved in anything remotely emotional, especially when she implies that she's going to get an abortion
Rhys: You're not gettin' rid of it!
Gwen: Is that right?
Eugene Jones' funeral in "Random Shoes". Particularly when his father sings "O Danny Boy".
Seeing who Owen was before Katie died, and comparing that with the bitter man he turned into afterwards.