Spider-Man - Peter Parker became Spider-Man after letting a burglar escape at a wrestling establishment that he was performing. That burglar later killed his uncle Ben, his own parents killed in a car crash years earlier. Peter learned "with great power, comes great responsibility."
He is a scientist and inventor, developing his own web fluid and web shooters. He has the proportionate strength of a spider and has a "spider-sense" that warns him of danger.
He has lost friends and loved ones to super villians, been cloned, been married, been mutated, and even became a host for a symbiote, and yet, he continues to fight the good fight. His shy and loner nature is overcome by his quick wit and wise guy humor.