This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Dead Rising 2
Dead Rising 2 charges you with making sure you maintain a daily supply of Zombrex to keep Katey, Chuck's infected daughter, from turning into a zombie. Should you fail in this, the game's story missions become locked out. When you return to the safehouse in anticipation of the military's arrival, however, the sheer weight of Katey's death makes Chuck suffer a Heroic B.S.O.D. as zombies breach the safehouse. With Katey dead, and with no reason to go on anymore, he does nothing as the zombies pull him to the ground and devour him. There's a reason this ending is graded "F".
Made worse by Off the Record: Katey apparently died and Chuck went insane, becoming a psychopath thinking a doll was his dead daughter. Watch this and tell me you didn't feel like crying.
Another thing to note about this is the boss music for this fight. The lyrics are all about somebody who's lost everything they care about and can only get by now by drinking themselves to death.
Frank's double Lampshade Hanging after the fact may have been intended to break the tension, but it might just make everything worse depending on how much of a Chuck fan you are.
In Off The Record, if you visit the Green Room during the initial outbreak (which is where Katey was hiding in the original), you'll see that her backpack is on the ground with smears of blood near it. That is just straight up depressing.
Oddly enough, Sullivan's death in Off The Record.
Frank: Thanks for saving my ass, Sullivan. You were a good man.
Also from the aftermath of that same scene, if you examine Rebecca's body:
Frank: You could have been great, kid... We could have been great...
The worst part is the fact that the whole thing could have possibly been avoided had Chuck simply not said "slow". Worst of all is that you can save Snowflake, but it is a total Guide Dang It!.
Slappy's death scene where he mourns the loss of Suzy before biting the dust qualifies as a little tearjerking if a little creepy too.
During one of the cutscenes where Chuck gives Katey her Zombrex, hearing Katey apologize to Chuck that he has to keep risking his life to get it is heartbreaking.
The aftermath of the fight with the Twins is unexpectedly sad. Before committing hara kiri on herself:
Surviving Twin: I will never be complete again...
Dwight Boykin's role in the game is saddening because he is the only Psychopath in the series that is shown becoming a Psychopath, when arriving in Fortune City he was admirable, showed loyalty to the men under his command, and showed that he truly wanted to save the survivors. When his squad was slaughtered in front of him, he was forced to flee and had become insane with Survivor's Guilt and began to attack the very survivors who he came to save from the outbreak.