Nobody loved The Big Combo back when it was released in 1955. Not the New York Times (an "...open-throttle monotonous serving of mayhem.")
Not Variety ("...a rambling, not-too-credible plot, and is cut out to order for the meller fan who likes his action rough and raw...".)
And then very slowly American film snobs and smarty-pantses began to catch on that this was actually a genre and suddenly a whole bunch of disposable B-movie melodramas from the 1940s and 1950s became classics retroactively.
"The Big Combo" is one such orphaned ugly duckling that grew up to be something much tastier than the original critics knew.
From Film Noir: An Encyclopedic Reference to the American Style: "There is a sense of fatalism and perverse sexuality found in The Big Combo that exists in few noir films...Much in the same way as Lewis's classic Gun Crazy, there is an affinity between sex and violence; and the exploration of futility presents an ambience strangely reminiscent of an earlier period of noir films, such as Scarlet Street  and The Woman in the Window . These attitudes combine with John Alton's photography to create a wholly defined film noir, as the striking contrasts between the black and white photography and Lewis's sexual overtones isolate The Big Combo's characters in a dark insular universe of unspoken repression and graphic violence."
Cops, criminals, and a dame who is bad news.