What Is the Fascination, the Beauty, of Film Noir?

Unlike daily news stories that leave you dirty and disgusted, the horrors of film noir could fascinate, even soothe and darkly uplift…

Classic film noir (~1940~1950) grew out of German expressionism and then the angst of The Great Depression; “grit and reality, in counterpoint to the American Dream - film noir is all about losers remaining losers.”

Lighting is critical in these haunting classics… “a perfect blend of form and content, where the desperation and hopelessness of the situations is reflected in the visual style, which drenches the world in shadows and only occasional bursts of sunlight…Harsh highlights and expressionist shadows are played to the max.”

So what is going on, why does the fascination now continue long after? Also, what is your favourite, and maybe do you just have some free association?

http://www.boxing.com/boxing_film_noir.html

First photo, closing scene from THE BIG COMBO; John Alton crafting many of the iconic images of film noir.
Second photo, beautiful Rita Hayworth did many pin-up photos but look at her depth of beauty in LADY FROM SHANGHAI. 
Third, a dark thriller panned at the time, A LONELY PLACE is now considered to be one of Humphrey Bogart's finest performances (and Gloria Grahame exquisite too, imo).