Pretty much the entire last quarter of Reaper Man was a tear-jerker for me, but it really hit home when Death told the new Death that he was fighting him because he cared about the people living on the Disc. This, of course, being the reason the Auditors of Reality fired him. Add in Death going after the little girl whose time had run out because Mrs. Flitworth smacked him, Death taking Mrs. Flitworth to her husband in the afterlife, and finally Death confronting Azrael about why Deaths need to have compassion so they aren't just oblivion, and I was crying my eyes out. Although really, anywhere Death reflects on the nature of his job is a tear-jerker for me, because that's something that really hits me.
What can the harvest hope for, if not for the care of the Reaper Man?
I have brought you chocolates. And flowers, the kind girls like. And I have also brought a diamond to be friends with you.
The talk with the dying Windle about why it is important to be needed by others and how it resonates in the final scene where he spares the Death of Rats (and the Death of Fleas) rather to be alone.
His experience with exterminating rats, where taking life himself makes him feel like a murderer.
His confusion when they're going to have a chicken for dinner.
Death: But we feed them.
Death killing the chicken, and how he's never killed anything, only taken life away when it was finished with.
He opened his hand. A tiny spot of light hovered over his palm. He blew on it, gently, and it faded away.
There's a scene which prety much summarises Miss Flitworth's personality, in which she talks about how after her fiancÚ died she was expected to spend all her time moping around in a decrepit wedding dress weeping, but instead she got on with her life. At the end of the book Death opens Miss Flitworth's chests that no-one has ever seen inside and finds it contains her old wedding veil; she still thinks about her fiancÚ.
Also: Miss Flitworth said that because you "don't waste a perfectly good feast," she still held the big wedding dinner even when her fiance had vanished. Imagine her sitting there, not crying, at this big party when everyone's whispering the worst about her fiance... Good lord.
One more, when she dies at the end. She becomes 18 again, the age she was when her fiancee died. She didn't REALLY move on, just refused to mope about it. But she waited for him, until the very end. And her belief that he, too, had been faithful to her until his death was entirely true.
That she offers the fine material of the dress as a whetstone for Death's replacement scythe in the same scene has so many different perspectives of meaning packed into it that I find at least a new one, usually another Tear Jerker, every time I read it. It only makes it worse that it barely helps, as little more than a stepping stone to the next, perfectly common thing they try.