6. Peter Parker Creates All Of His Problems - Spider-Man
The Plot... It's almost a cliché to state that sometimes superheroes cause as more damage than they stop thanks to all those supervillains they inspire. Nowhere is this more potent than in Sam Raimi's Spider-Man Trilogy, where his actions aren't totally positive for the citizens of New York. Think about it; after killing the board of directors the Green Goblin becomes all about hunting down Spider-Man; Doctor Octopus becomes obsessed with redoing his experiment because Spider-Man got in the way; Harry wrongly thinks Spider-Man killed his Dad so becomes the second Goblin; Eddie Brock is purely motivated by his hatred of a successful Peter Parker. The only one who would exist even without Peter Parker's involvement is Sandman and even then he's directly tied into Spidey's origins. So not only is the death of Uncle Ben a focal point in Peter's life, but it completely shapes the crime of New York City. The same isn't true of The Amazing Spider-Man series, where Oscorp are so all out evil that they've been meddling and scheming from when Peter was a kid.
Why The Main Character Should Have Just Stood Still... We mean literally stood still exactly where he was. In Raimi's version at least, Peter has the opportunity to stop Uncle Ben's killer when he robs the wrestling game, but stubbornly lets him escape. This directly lead's into Ben's death, which is the main motivation for the creation of Spider-Man; without this event he'd be a more balanced person and the big baddies wouldn't have been motivated to be so evil. And, of course, this also would mean Sandman never shot Ben (urgh, retcon) and thus the final villain is tied to this one point. This is a defining part of the character in the comics, with Peter's guilt over the death of his Uncle providing the ensuing motivation of the character, but in the first set of film's it clearly has a bigger effect.