It's become almost a given that a blockbuster sequel will be bigger, but not always better, than its predecessor. Spider-Man 2, for example, sheds the necessary origin restrictions of the first film, and embraces its comic book inspirations whole heart. Yes, there's still an origin story, but this one focuses on the creation of Spider-Man's villain, Doctor Octopus - played to great effect by Alfred Molina.
Obviously, the origin story is important to the overall property, but getting to go full throttle with the action, at the very least, makes the second film more exciting. And that bigger action, combined with better character work and higher stakes help cement Spider-Man 2's place as the best film in the Sam Raimi trilogy. We wouldn't go so far as to say Spider-Man 2 created the superhero sequel formula, but it certainly perfected it. So much so that the reboot is following the trilogy's formula (thus far) almost to a "T."