There are ALOT, trust me.Most of them you see in Justice Leage and Justice League Unlimited.Heroes like Spider-man, Ironman, and the Hulk are from Marvel Comics, NOT Dc Comics.
That would be Superman. He was the first superhero, actually. Before him, there were superhero-like people, such as Zorro, The Phantom, and The Shadow.
the are 6,80092 about including villain's, x-heros, unscanned heros and bio-s herosunscanned hero's=heros copied off over heros EG: killer moth, Andrew crush and joyrider bio-s heros=banned heros...
God, tons in the mainstream Marvel universe (616) have died but most came back. Spider-man died in "The Other" but was resurrected.Captain America was killed in "Death of a dream" and came back a few...