Norman Osborn (Sam Raimi movie series)

The Green Goblin is the main villain of the 2002 Sam Raimi "Spider-Man" movie and based on the Marvel Comics character of the same name. He was played by Willem Dafoe in all three movies and the first tie-in video game.
Background.
The designers wanted a more comic-accurate design for his suit, but many considered the mask too creepy, so they went with the helmet seen in the movie.
Fictional biography.
Norman Osborn is the CEO of OSCORP and father of Harry Osborn, the best friend of Peter Parker. After being pressured by the American government to complete a project for them, Norman tests the project – a drug that is supposed to turn people into super-powered soldiers – on himself, turning himself into the crazy, evil Green Goblin and developing a split personality. After Peter becomes Spider-Man, he battles the Goblin several times. 
Norman eventually finds out Peter's secret identity, then attacks Peter's Aunt May and crush Mary-Jane Watson to try to bait him. Peter, as Spider-Man, manages to defeat the Goblin before Norman reveals himself. Despite finding out his best friend's dad is the Goblin, Peter refuses to work with Norman, who then tries to kill Peter but ends up killing himself instead. Harry then thinks Spider-Man killed his father, not knowing about the bad things Norman did as the Green Goblin until later in the movie series.
Reception.
Willem Dafoe's portrayal has been well-liked and considered one of the best movie supervillains of all time despite his design.