This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Savannah Reid Mysteries
Everything involving Dirk when Savannah gets shot in A Decadent Way to Die. Especially the moment when he starts crying - only the second time we've seen him cry - and then the other three (Tammy, Ryan, and Gibson) join in too.
In Killer Gourmet, Savannah spends a lot of the book feeling ill and getting dizzy and eventually she goes to see a doctor. After the doctor asks her how long it's been since her last menstrual cycle, Savannah realizes that she might be pregnant. She thinks about how Dirk would make a great father and how he'd be happy about it, and she pictures them telling all of their family members and friends, and seeing the joy in their faces: Granny, and Tammy and Waycross, and Ryan and John... And then the doctor tells her that she's starting menopause, and those dreams come crashing down around her ears.