Kyle: I got robbed. Sorry, I know that I bitch constantly about losing these debates. But I got robbed. The Death of Superman arc is much worse than Knightfall. And here are three more reasons why.
One, when comic fans look back at the horrible crap that we had to deal with in the '90s, this is usually the first thing that comes to mind. While Batman was riding high from the success of movies, cartoons, and the new darker approach that the comics were taking, Superman got a mullet and died. And got replaced by a robot. In a bad time for most comics, this was the most blatant misfire of all of them.
At the time, nobody was buying that DC was actually killing the most iconic superhero in the world. And lo and behold, they didn't. It was a little game that we all had to play: Go ahead, you "kill" Superman. Then I'll count to ten and run into the comic book store looking for him. And I'll find him. Safe and sound.
Two, in the context of our title (Worst Superhero Death), I let Chris play fast and loose with Knightfall as a death. But even counting it, at least Batman's fall and rise meant something. He had to wrestle his rightful place back from an edgier, more '90s character than he was. And he kicked the living crap out of this new '90s take on vigilantism and said, "This is how I do things. And that's how it will continue."
Meanwhile, the Death of Superman meant nothing. There was no catharsis or motif or exploration of the character. Not even the obvious he-was-a-shining-example-for-us-all-and-his-final-lesson-was-giving-his-life-to-save-us bit. They didn't really do anything with this monumental story they could have told. Plus, because the book was titled Death of Superman, we had a Brechtian hold on any emotion we could have mustered, because we go in knowing that he's going down. Knightfall at least built up to the climactic moment and gave us the sucker-punch of Batman losing.
Three, here's the deal: Death of Superman is clearly worse than Knightfall, but it also beats out the Jean Grey, Lian Harper, Captain America, and actual Bruce Wayne (R.I.P.) deaths. Why? Because this was the first widely announced superhero death that proved that no one stays dead. It was the first case of "death ... kinda ... hibernation ... time travel ... alternate universe ... no, not death at all."
All comic-book deaths mean nothing, mostly because the people aren't real, but also because there are now so many different continuities and alternate universes and lenses that we see events through (Frank Miller Batman is clearly different from Morrison's which is different from Paul Dini which is different from, etc). Quibbling over which death is canon and which isn't is a waste of time. It's like the new J.J. Abrams' Star Trek movies. It doesn't cancel out, destroy or wipe away the original continuity, so it's okay.
But Death of Superman was artificially made important from the beginning. It permeated beyond the comic geek community, beyond the Warner Brothers/DC profit-grabbing meetings, and beyond the random movie fans. It made headline news in the real world that this fictional character was being killed off. So all of this makes it a bigger slap in the face and a bigger piece of crap in the history of mainstream comics.