5) Generation Next (Age of Apocalypse) - Poor kids in a literal apocalyptic hellscape got sacrificed by their teacher Colossus who couldn't give 2 shits about them in order to save his sister
4) Shadowcat (Age of Apocalypse) - Got trampled by her husband Colossus who was trying to save his sister (notice a theme with this asshat.) She thought he loved her enough to stop that she didn't even use her powers to phase through him.
3) Aeris - yeah, we all took this one in the feels 20 years ago.
2) Dobby the house elf - Seriously the only genuinely 100% good character in the books who had no ulterior motive. At least he died a free elf.
1) Professor Xavier (Logan) - God I was literally in tears at that moment