an adaptation must stick to the original.for me,an adaptation is the way to show the story in motion pictures rather than just words or still pictures as in graphic novels or comics.that's why the movie must stick to the original story line,characters,timeline n etc so that it won't be different than the original.the way the director manages to picturized(i cant find the suitable word for now) the original story is very important.only good director can produce great adaptation.tim burton's batman is my all time favourite.he really show how dark bruce wayne is and how annoying joker can be.