Tear Jerker / Mobile Suit Gundam Wing

• Episode 17 "Betrayed by Home, Far Away". Gundam Sandrock independently choosing to eject Quatre and commit a Heroic Sacrifice.
• Episode 25 "Quatre VS Heero". Poor Quatre, after having become highly unstable thanks to the newly constructed Wing Gundam Zero. Which has led him to go on a rampage, destroying several colonies. Trowa goes so far as to fight him, prepared to die in order to snap his friend back to reality. All while Heero forces Quatre to watch as Trowa seemingly gets himself killed. Fortunately, Trowa does survive... but the whole situation is still rather traumatic for poor Quatre.
• Dorothy, when she shreds her facade and panics after Zechs decides to reject Treize's peace offer and blast his mobile suit. This is the first time that she ever shows raw and real emotions without bothering to restrain them (like when Duke Dermail died and she was shocked for a while, then recovered and used it for a Rousing Speech) and begs him to not do that, going as far as screaming a Big "NO!" and struggling with Zechs while still pleading for Treize's life.
• Treize's death. The way he went down with such grace was gut-wrenching.
• Trowa being forced to destroy Deathscythe, or else blow his cover. Duo freaking out was bad enough, but Trowa's shock as he notices his own tears floating around him was so sad.
• Duo finding an amnesic Trowa at a circus and being excited to see him alive and well, only for the usual calm and quiet Trowa to undergo a panic attack and Catherine shouting at Duo to leave.
• Heero's speech to Wufei in Endless Waltz. Specially when in a small and soft voice, almost a whisper, he asks Wufei "how many more times must I kill that girl and her dog?"
• Relena's brief Heroic BSoD when her adoptive father is killed. Also, her reaction when her mom is about to tell her the truth about her heritage as the Princess of the Sanc Kingdom:
  Relena: [hugs Mrs. Darlian] Please, mother, don't say anything! Just... Don't stop being my mother!
• Otto's death. "LONG LIFE KING ZECHS!", indeed.
• One from the beginning: the death of a young Oz cadet in Noin's arms, after the bedrooms are bombed by Wufei. "Milady, I'm sorry... I really wanted to go into space...!"
• The manga spinoffs also have their share of sadness. The Heroic Sacrifice of Marticus Rex aka King Peacecraft (which is also a tear jerker in story as his former butler Pagan tells Relena how her biological dad died to save both of them and the man who would adopt her as his own child, Duo's backstory as a whole (especially Sister Helen's death), the passing of Heero's caretaker Odin Lowe Jr., No-name's confrontation with Middie Une, the girl who loves him and yet still betrays their group to help her family., and the death of Wufei's Plucky Girl wife Meiran.