Here are some of the most famous instances where Superman has been killed:
* Doomsday (DC Comics): This is perhaps the most iconic Superman death. In the "Death of Superman" storyline, Superman was killed by the powerful villain Doomsday.
* "The New 52": In the rebooted DC Universe, Superman was killed by the villain Darkseid.
* "Injustice: Gods Among Us": In this alternate universe storyline, Superman was killed by Batman after becoming a tyrant.
There are many other instances where Superman has been killed or seemingly killed in comics, but these are some of the most notable.
Do you have a specific story or comic in mind? If you tell me which version of Superman and which story you're interested in, I can give you a more precise answer.