Most of the final chapter. One that is especially string-touching is Laurie and Daniel making love. Who would've thought genocide could make way for such a sweet moment?
The scene where the newsstand guy, in face of certain death, still attempts to protect the kid he's been arguing with for the majority of the comic. Note this is especially notable in the comic, as the two characters only have mere cameos in two of the three cuts.
A retroactive one: "I'm still me Joe. Pull over."
Rorschach's joke when talking about the Comedian.
Rorschach: He saw the true face of the 20th century and chose to become a reflection, a parody of it. No one else saw the joke, that's why he was lonely. Heard a joke once: Man goes to doctor. Says he's depressed. Says life seems harsh and cruel. Says he feels all alone in a threatening world where what lies ahead is vague and uncertain. Doctor says "Treatment is simple. Great clown Pagliacci is in town tonight. Go and see him. That should pick you up." Man bursts into tears. Says "But, doctor...I am Pagliacci." Good joke. Everybody laugh. Roll on snare drum. Curtains. Fade to black
As Rorschach and Nite Owl confront Ozymandias, the scene is interspliced with a scene of two people arguing, and ordinary people from the street coming in to stop them hurting each other. Then Ozymandias' plan is revealed and all of them die regardless.
Rorschach's last few panels, when he rips off his mask and reveals that Veidt's mass murder of New Yorkers has made even this notoriously emotionally-dead man weep.
Rorschach's death scene. One of the saddest moments in the film. "Suddenly you discover humanity. Convenient. If you had cared from the beginning, none of this would've happened."
When Rorschach crosses the Despair Event Horizon. The audio indicates that he's actually crying under the mask. This has to be a Crowning Moment of Awesome for Jackie Earl Haley's performance — you can see him crying under the mask and his face contorting in emotional agony. To be able to relay that through a mask designed to hide your face. Just wow.
Jon Ostermann's "death". He gets better, but still. The narration, the music... everything came together perfectly.
The Director's Cut has the death of Hollis Mason, which include him putting up more of a fight than in the comic, and intercutting the punches to flashbacks of busting up badguys. So many Manly Tears...
I lost it when I finally saw - you guessed it - the left hook that floored Captain Axis.Hope Spot much?
"Sorry, girl." Even worse in the French dub, where it's "Pardonnez-moi, ma belle."
Mothman being taken to the insane asylum during the opening credits, especially combined with the music.
Also from the opening credits, the atomic bomb being dropped on Hiroshima, and the National Guard opening fire on protesting students, both quite genuine events from history.
Edgar Jacobi, who has retired from being Moloch, and now an old man, talking to Rorschach, who has just pulled a bottle of pills from one of the kitchen drawers:
Edgar: Please... don't confiscate that. I'm trying anything. I .. have cancer.
Rorschach: What kind of cancer?
Edgar: You know the kind you eventually get better from? (he smiles, which turns bitter after a moment) That ain't the kind I got...