Although some of these do not strictly fit the original, classic definition of a dark, gritty, urban setting in which an average guy gets caught up in circumstances beyond his control and is brought down by a femme fatale, I still think of them as at least "noirish." The more classic examples would include "Out of the Past," "The Postman Always Rings Twice," "Kiss Me Deadly," and "Double Indemnity".
A list by PT 100