Because revenge is a very known feeling in American culture, there's a certain element of an eye for an eye. There's the saying, 'Be careful what you wish for, you might get it.' When you wish for revenge, and you think you've gotten it, what happens then? Revenge is just a really good drive for drama and good action.
I think 'The Girl with the Dragon Tattoo' is a good example of a film where you have to juggle a whole lot of information to follow that story, and even if you haven't read the book, it seems to go pretty well. And that is a film where the characters didn't meet until 74 minutes into the film, not on page 17.
We need to keep examining evilness. For instance, I'm totally against the fact that Osama bin Laden was shot. I think that he should have been put on trial and exposed as that human being he was. I think he should've been standing mentally naked in front of the rest of us and stand to justice for what he did.