Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Sam & Cat
When Sam and Cat are sleeping together the first night Sam meets Cat, she tells Cat that she has no reason to go back to Seattle any time soon since her mom isn't totally well (adding to the fact that she mentions later that living with her mother is like living alone) and especially because Carly moved to Italy with her dad at the end of iCarly. Although she was still friends with the other characters, not even Freddie, who she dated for awhile and had admitted that she was in love with him, was enough of a reason for her to stay.
Seeing the always upbeat and perky Cat turn into a depressed heap in #FavoriteShow when her favorite show gets cancelled.
Just about any time Cat looks sad. Ariana Grande is way too good at it.
Jennette McCurdy gets her turn in #Yayday. It's just as bad as when Ariana does it, if not worse.
Dice saying Goomer is his best friend (he's only known him for a few weeks) gives a sad insight on his school life.
Goomer's mom saying one of the nastiest things ever on a Dan Schnieder show after she learns Goomer is in the MMA
Mrs. Merr: When I adopted you, I should've kept the receipt.
Almost all of Ms.Merr's interactions with her son are heartbreaking.
Sam coldly swindling Cat out of all of her money at the start of Revenge Of The Brit Brats. Considering how she easily gave up a portion of money in the pilot... that's cold.
Also, Sam and Cat's arguing is hard to watch after all of this time seeing them as great friends.
Sam and Cat's argument in #KillerTunaJump is very sad, especially the part where Cat tells Sam that she doesn't care if Sam jumps over the killer Tuna. In context, it sounds like a kid friendly version of "I don't care if you die."
The entire second half of #YayDay
Sam's card to Cat. Dear lord, the card
Sam: Most people I hate, but you I like. I'm glad we're friends.
It becomes worse when you realise that this episode was shot a week or so before Jennette McCurdy's mom died in real life. Watch the part where Sam mentions her mother again and try not to cry.
It doesn't really help that Cat never tells her her real gift and lets her know she switched gifts.
Dice's abuse in episodes like #Lumpatious is this. He's willing to help them out with any problem they have, and he gets no respect and a bloody nose for his troubles.
A meta example- the show's cancellation means that unless Dan convinces another actor from Victorious or iCarly to come back, the era of those two shows is now well and truly done.