One of the reasons thatJames Gunnhas been so successful making films for both Marvel and DC is that he appears to be a genuine comic book buff with a vast knowledge of literary history. While many directors choose to make comic book adaptations based on the career opportunities that they may provide, Gunn has been incredibly passionate when talking about the characters, films, and storylines that inspired him.Gunn cited the South Korean action thrillerOldboyas one of thebest comic book films ever made and mentioned that it “reinvented action” for the entire industry. AlthoughOldboyis well-regarded as one of the best films ever made byPark Chan-wook, it's easy to forget that it was based on a popular Japanese manga of the same name.