Filmed in the early 1970s, Chinatown is almost an essay, or cinematic study, on the film noir genre: everything about its creation is from the outside, looking in. First: even though the term "film noir" originated in France, it's a genre almost wholly American (at first). It would, however, go on to inspire a whole generation of filmmakers across the world. One of these is Roman Polanski, who helmed this brilliant genre study. At its heart is Jake Gittes, played by Jack Nicholson in one of his most defining roles. The Gittes character is one of the main reasons, apart from the villain and incredibly intricate plot, that this study works so well. He is the quintessential P.I. character with a reluctance to get involved and a moral code embedded in shades of grey. Incredibly slick when he needs to be and usually one-step ahead when it counts, he's one of those incredible characters you can't take your eyes off of.