This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Wing Commander
In Wing Commander, failing to eject before your fighter is destroyed results in a game over screen that consists of your character's military funeral. It's strangely depressing in a way that makes players very careful to bail out if their shields get too low.
Hell, any of the character deaths in the series are the same as this.
Liz (Shadow) from Wing Commander 2, for example, was just a reserve. Not expecting Kilrathi attacks and was mere months from retirement.
Also Kien Chen (Bossman) who during Secret Missions 2 is killed while on patrol with Angel, a death she blames herself for.
Also Spirit in Wing Commander 2, who had been blackmailed by the traitor with her long-lost fiancee's life and ultimately commits a suicide run against the station he's on after her fighter is sabotaged, and all Blair can do is watch helplessly.
Spirit's final words to Blair: Tengoku de omachishi te imasu (I will wait for you in heaven).
The destruction of Goddard in Secret Missions 1, where you are greeted by the haunting site of the devastated world filled with wreckage and bodies after it has been laid to utter waste by the Kilrathi, and the Tiger's Claw arrives too late to stop it.
Becomes this on a meta-level when you learn it was your earlier failure to save the planet that becomes Jazz's primary motivation for betraying humanity. As fate would have it, his brother was among the quarter million victims claimed by the Kilrathi.
The first scene of Wing Commander 2 is of you witnessing the destruction of the Tiger's Claw taking nearly everybody with it; and it's ultimately you who takes the fall for what happened.
Wing Commander 3 has the betrayal of Hobbes, in truth a Kilrathi sleeper agent who was working behind the scenes against his human comrades after being "reactivated" by Thrakhath. During his escape from the Victory he murders Cobra, who had always suspected the worst from Hobbes and ultimately dies before Blair as Hobbes makes his getaway. The profound betrayal Blair feels from someone whom he trusted and defended to the point where he literally flies into a rage against his old friend is truly saddening, especially as Hobbes himself had genuine affection for his human comrade even in betrayal.
Further amplified by the fact that if you do choose to pursue and kill Hobbes, the Victory is ambushed in your absence and the young optimistic Vaquero does not live to tell about it. Eisen's bitter admonishment of the Colonel as he holds the young pilot's beloved guitar is truly gutwrenching, as Blair knows he is to blame for the needless death of a fellow wingman. Even worse, according to the Novelization, this is the canon path.
The sad sight of the Concordia wreckage on Vespus, aflame and with its entire crew dead and entombed within, the mighty warship's bow peering out pitifully above the tides.
Locanda IV's fate if you fail to stop the biological warheads from striking the planet; everybody on the planet is dead.
Thrakhath's recording of Angel's execution on Kilrah; Blair handles it about as well as you could expect of anyone forced to watch their loved one being disemboweled.
Wing Commander 4 has a particularly hard-hitting losing cinematic if you continually fail your missions: Blair is brought before Admiral Tolwyn, who, in light of Blair's poor performance, revokes his commission, essentially firing him. Blair holds out his hand, offering a final handshake, which Tolwyn silently refuses. After taking his leave, Blair is last seen in a dive bar, drinking his sorrows away as the TVs in the background show the war waging.
Vagabond's death; to lose your old wartime buddy from the last game is bad enough, but to see Maniac moping over his beloved deck of cards...Truly, humanity has lost one of its best.
Catscratch's death, depending on the actions of the player. A young, ambitious rookie who was emotionally torn over the civil war erupting within humanity who nonetheless proved a loyal wingman to his comrades, and he finds himself cornered by the mercenaries, which forces the player to decide whether he is worth the risk of rescue or not. If the player is unable to retrieve him, he bids farewell to Velina Sosa, who doesn't have many kind words to offer Blair when he returns to the Intrepid.
The fate of everybody on Telamon at the hands of the Gen-Select Bioweapon; As Blair sums it up, it's simply evil.
The downfall of Admiral Tolwyn. Sure, he may be the bad guy and he was rightly punished for his crimes against humanity; All the same however, to see such a noble and decorated warrior so committed to humanity's preservation and perseverance through the entire Kilrathi War fall so completely from grace is truly a pitiable sight to behold. So incensed with not having tasted the glory of being the one to spell the end of the Kilrathi's vast empire and so obsessed with ensuring humanity's survival that he soon enough was no better than the monsters he fought against as he resorted to unethical and genocidal means, all in the name of his people's assured survival over the centuries to come.
Even worse in the novel version, where while awaiting his execution realizes that his plans, had they been realized to their full fruition would've only served to destroy humanity rather than assure its readiness for future threats in the long run, and that the cost demanded by his vision of genetic purity would be greater than humanity could ever afford; Ridden with guilt, he soon after hangs himself to death.
The death of Blair during the final assault on the alien wormhole during the events of Prophecy, personally boarding and sabotaging the station at the cost of his own life to ensure the survival of humanity against a far larger invasion by the incoming Nephilim.