The Long Goodbye (1973) from Johnny Web (Uncle Scoopy; Greg Wroblewski)

1. Philip Marlowe has traditionally been played by such macho icons as Bob Mitchum and Humphrey Bogart, who limned a portrait of a laconic, wisecrackin', tough guy. Eliot Gould kept the wisecracks, but played the private dick as an eternally chattering pussy.  He did more mumbling in this movie than Milton the Stapler Guy did in Office Space. Those previous Marlowes were lady-killers. Gould plays Marlowe as a slob and a chain-smoking douchebag who couldn't get laid in Vegas with a fistful of hundreds.
2. The story takes place in the 1970's instead of the 1940's, although Marlowe drives a 1940's car. The intention of the car, of course, is to symbolize Marlowe's anachronistic values in a world of amorphous morality.
3. Director Robert Altman played this about halfway between a 1940's movie and a parody of 1940's movies. One example: do you recall how old movies use a single musical theme for a character, which is played again and again at different tempos or in different keys depending on the mood of that character? Altman features a whisky-voiced jazz-blues version of "The Long Goodbye" in the opening credits to familiarize us with the tune, then uses this melody as virtually the entire musical score. If Marlowe is in Mexico, he hears a mariachi version. High school football game? A marching band version. Funeral? A dirge version in a minor key. And so forth.
4. Eliot Gould and Sterling Hayden are about the only professional actors in the cast. The supporting cast features people like Danish model/socialite Nina van Pallandt, who had never before appeared in an English-language movie, baseball pitcher Jim Bouton, concept comic Henry Gibson, and bodybuilder Arnold Strong (whom we later came to know and love as Schwarzenegger).

Although he updated the story and the character to the 70's, Altman did retain certain key elements of the storyline and Philip Marlowe's personality. The film ends when Marlowe commits an act which most of us would consider to be a form of immoral vigilante justice. Yet it is consistent with his belief system and his own sense of integrity, and that action allows the film to pull back from campy fun and re-establish the proper noir tone. Marlowe is supposed to be a guy whose values and standards are higher than those of the people around him, and Altman manages to convey that. The original Marlowe didn't belong in seedy, corrupt L.A.. The new Marlowe, with his cheap J.C. Penney suits, and his inflexible sense of right and wrong, doesn't belong in the Age of Aquarius.

I think if you just forget that the character is supposed to be "Philip Marlowe" and allow yourself to view it afresh, you'll find it an interesting film.