Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Marley And Me
The end of the book wherein it's described that Marley had to be put to sleep because they couldn't really do anything. This was also made pretty bad in The Movie too. It's probably one of the most triumphant examples of a Tear Jerker in the 20th-21st century because of how close to home it hits, since people are much more likely to experience the death of a pet in their lifespans; even children. Very reminiscent of Old Yeller without shooting the dog.
Carrot Top has on several occasions done a joke where he is on an airplane and they say the in-flight movie is Marley and Me. Carrot Top says "No! not that!" and by the end of the movie, almost the entire plane is in tears.
This is arguably not even so much of a YMMV! Book clubs often avoid this book because it had a tendency to make the readers cry. Schools don't often put it as reading material because students have been known to burst into tears near the end. And in the theatres? Theatre workers have reported seeing a lot of people leave teary-eyed...and these weren't the kids. You could tell who the pet-owners were in the theatre because they were the adults crying.
Not so much that the dog died, but that it succumbs to freaking hip dysplasia, unable to run, climb stairs, and has difficulty even standing. And yet insists upon following his master from room to room despite this. Watching the wild, energetic dog slowly wind down to a dull-toothed, deaf, and hobbling animal is heart-numbingly sad.
This above. I was crying at the point where Marley was struggling up the hill alongside John, and they just sit together and John basically pleads with Marley to tell him when he's ready to pass on, because he loves his dog and he doesn't want to see him in pain.
"Marley, you are a great dog."
Jenny's miscarriage. They come home from the doctor's office all somber and subdued and the heretofore rambunctious Marley simply quietly rests his head in Jenny's lap. The book takes the scene even further than in the movie, with John joining her on the couch and the two of them sobbing as Marley sits there with them.