Death is something superhero comics have struggled to really deal with, pretty much since they first began. Writers constantly strive for the perfect balance between ensuring death feels consequential, and retaining the fantastical nature of superhero funny-books. This has had the unfortunate side-effect of making every 'death' in both the pages of Marvel and DC tending to feel just a little meaningless, with resurrections plentiful and near-instantaneous.
Point being, it doesn't take a lot for a 'death' to get botched completely, and when you factor in the medium's obsession with 'women in refrigerators', genuinely affecting deaths are hard to come by.
No single publisher emerges better than the other either. Both halves of the 'Big Two' have spotlighted some truly egregious comic book deaths, featuring heroes, villains, and more - even as recently as this year.
Although her fate is yet to be sealed, the cover for Heroes in Crisis #6 seemed to exemplify almost everything wrong about the superhero genre's approach to death.