So there's three Filme based upon Bücher from Stieg Larsson. I usually don't like Filme like this, but I loved them all, especially because of the main character.
It's about a girl, named Lisbeth Salander. She's a loner and... uh... something special. She is a hacker, and helps her friend, a journalist named Mikael Blomkvist. They try to gain information about a family named Vanger, but they both discover things that involves themselves.
This is a very short summary of... uh, well, at least one of the movies, but I have just started on the books, so I can't tell Du so much about them. But trust me, it is a movie worth watching, although it's kinda brutal.