The number one movie on our countdown is one of the most engrossing films of the new millennium, a film designed to make the viewer hang on every single piece of dialogue and pay strict attention to every clue given. Zodiac, directed by David Fincher (Gone Girl) and starring Jake Gyllenhaal, Robert Downey Jr and Mark Ruffalo, tells the tale of the people who tried for many years to discover the identity of the Zodiac serial killer, who terrorised the San Francisco Bay Area in the late 1960's/early 1970's. It is a story of obsession, as the case becomes all consuming for Gyllenhaal's Robert Graysmith, a young newspaper cartoonist who was working at the San Francisco Chronicle newspaper when the Zodiac killer was sending taunting correspondence to the paper's editor. Graysmith wrote the book that the film is based on, where he details his own personal investigation and says who he believes is the Zodiac. The film also follows the members of law enforcement who dedicated their careers to the case, including Mark Ruffalo's Dave Toschi and his partner Bill Armstrong, played by Anthony Edwards. Zodiac is one of the most detail oriented investigation films ever made, with Fincher (who is well-known to be a stickler for details), screenwriter James Vanderbilt and producer Brad Fischer actually spending 18 months before filming began conducting their own research on the case. None of this makes the film dry or dull, however. Rather, if you let yourself be consumed by the film, it will stick in your brain for many weeks and months afterwards. It's a testament to the craft of the film that it doesn't hurt the story in any way that the real Zodiac was never caught. Instead, the lack of closure and resolution is another aspect that lodges itself in the viewers head. Have we left out any crime classics from the 2000's? Think any of our choices are suspect (see what we did there)? Sound off in the comments below!