I got a few:
In Rdr2 my fully bonded horse died in the middle of the fight. My beloved Chelsea II was there from the beginning, when Hosea gave her to me. She died while I was fighting some bandits
I died in my Minecraft hardcore world. It kinda made me sad thinking my horse, Gina, my 2 cats, Kim, Kourtney and Kylie, my 6 dogs, Artemis, Achilles, Apollo, Aphrodite, Ares I and Ares II and parrot, Loki were still there, awaiting my return
People will probably hate on me for this one but when Elise died in AC unity. Got me right in the feels!
My 90 hour Fallout New Vegas saves being lost forever
The enslaved Vortigaunt on the HL2RP server would sometimes sneak off from the Combine and hide out in an abandoned shop.
To my character, traumatized, terrified of this new horrific dystopian world, they were my only friend, my confidant, a source of support in this depressing city.
Raids increased, Combine got more vigilant, day game that she never saw them again.
Alien Isolation. I was at a point where human was in the way of me progressing forward. So i threw a noise maker in his direction to lure the alien into killing him. Right after i threw it he gave if voiceline where he says that want to see his wife again. I made the decision to kill him in this moment knowing full well that i could have sneaked past him. I just thought killing him was easier.