This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Black Company
The Black Company contains a lot of sad moments with the sheer number of characters that die there. One of the most touching scenes comes at the beginning of the 5th book. The company, reduced to small group of cynical veterans prepares an ambush for a group of bandits. The team mages prepare an illusion to make the enemy think they are hopelessly outnumbered. As it turns out they shape it using their memories, conjuring the images of all their fallen comrades until the company stands several hundred strong, returned, for a brief moment, to its past glory.
In the final book, Narryan Signh, in an act of desperation, strangles a dog to feed himself and the daughter of the night (A.K.A Booboo). What makes this particularly heart wrenching is that it shows just how much Narryan's faith has woven (whom by the time of Water Sleeps, was a level 20 Zealot according to the D20). Since his actions offend himself on so many levels. As a Hindu, he is a vegan who doesn't eat meat; and as a strangler/thugee he mustn't strangle innocents, as such actions would stop the stranglee from reincarnating.
Late in Soldiers Live, Croaker learns that the fabled Khatovar, a dream that he has been chasing for half his life, was conquered and razed by Voroshk generations ago. There is no Khatovar for the Company to return to.