Chinatown is undoubtedly a good movie. It takes common old film noir elements, and it subverts them, and plays on the audience's expectations, and use them to create a movie that is even more twisted and depressing than film noir usually is. I mean, this movie leaves The Third Man in the dust on the darkness scale, even without Orson Welles. Chinatown does have Jack Nicholson, though, and I've said that before, and I will say it again: There is no one scarier than Jack Nicholson. And he's terrific in this movie - this is before he started doing that sneer-y thing, so he looks totally different than usual.
I was definitely entertained while watching the movie, but it hasn't really stuck with me. When I think back at it, I like the mood, but I almost never think about it. I think of a lot of the other movies I've watched almost constantly. Chinatown just hasn't made an impression on me. Good imagery, though - The nose-bandage will really stick with me.