The Treasure of the Sierra Madre - B. Traven
An uncommon sort of adventure story.

At times, Traven's journalistic roots show, when he seems more interested in depicting the setting of the story and its social conditions than in moving the "plot" along. For instance, in the first chapter, he spends 13 pages describing the Hotel Oso Negro in far more detail than is necessary for the few brief scenes set there. Traven knew the places and people in this story from first-hand experience. It was a wise choice for him to write a novel, even if he was a journalist at heart; few enough people read journalism when it is first published, and even fewer later, but a good novel keeps on being read.

More than that, however, The Treasure of the Sierra Madre is a moral tale. That is not such a contradiction as it may seem, since journalists in the early part of the century were often far less reluctant to draw morals than is thought of as the standard today. The structure of the novel is really a series of linked stories of the desire for gold, its dangers, and the alternatives.