Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Homeworld
Homeworld. The entire Goddamn story, especially in the first installment. The first minute of the "Return to Kharak" mission is especially worth mentioning. When the Mothership returns to Kharak, and the camera pans to see the entire planet being consumed by a firestorm, and Agnus Dei (the choral version of Barber's Adagio for Strings) starts playing in the background...
Fleet Command: No one's left. Everything's gone. Kharak is burning...
Not to mention the fact that freakin' Karan S'jet sounds emotional when she says this.
Fleet Intelligence is also barely holding it together; you can hear his voice crack a little at the end.
Fleet Intelligence: The scaffold has been destroyed. All orbital facilities destroyed. Significant debris ring in low Kharak orbit. Receiving no communication from anywhere in the system... not even beacons.
There's another heartwrenching line in that level: You've loaded the remaining cryotrays on board, the ship is powering up to warp away and then you hear this:
Fleet Intelligence: There's nothing left for us here. (sigh) Let's go.
After the Kushan save the Bentusi from the Taiidan Empire, the Bentusi see fit to share with them information that was forbidden from being shown throughout the entire galaxy. What information is so important and so illegal that it requires saving the lives of the most powerful alien race in the galaxy to be shown? The exile of your ancestors from Hiigara. The entire sequence is shown as an entire fleet of prison ships running on very basic and unreliable machinery makes an unplanned journey across the galaxy on conventional drives, resulting in generations after generations of Hiigarans living as nomads throughout space until they reached Kharak on the edge of the galaxy. You also see several prison ships losing control and exploding due to shoddy machinery, and others abandoning the course and deciding to live elsewhere, resulting in the Kadeshi. All this goes by while Samuel Barber's "Agnus Dei" is playing in the background, just driving it further into you the tragedy the Kushan face as a result of the sins of their ancestors, and even they faced a horrible fate. The entire legacy and future of the Hiigarans/Kushan is just one big tragedy, all the more reason for you to help them see it through to the end.