Christopher Nolan’s 'The Dark Knight' was a transformative blockbuster that redefined what a superhero movie could be. It grossed $1 billion, but its legacy is tied to Heath Ledger’s performance as the Joker. Ledger died shortly after filming, and the subsequent praise for his role turned the film into a global 'event.' It was the first time a superhero film received a posthumous acting Oscar. The film’s gritty, realistic 'crime drama' tone influenced a generation of blockbusters, moving away from the campy style of earlier comic book adaptations. It also led the Academy to expand the Best Picture nominees from 5 to 10 after the film was controversially snubbed for the top prize.