The first Leaphorn and Chee novels, by Tony Hillerman, were fun to read even though I don't care about mysteries, because they could be read at several levels at once. There was the basic plot (the mystery to be solved), the back story (Jim Chee's love life, Joe Leaphorn's wife dying and his retirement from the police force), and the "what it's really about" level (usually some variation on belonging and not belonging). The interplay between the three levels made the stories compelling novels, not just mysteries.
Unfortunately, as the series went on, Hillerman seems to have lost interest in it. The deepest level, which raised the first novels about the genre label, disappeared somewhere before the middle of the series. Then the back story started fading, becoming an armature to drape the plot on rather than a carefully-built structure of its own; Skeleton Man was almost exclusively plot. In The Shape Shifter, the last book (so far) in the series, the back story has gotten confused and even the plot is suffering. It isn't really even a Leaphorn and Chee book, since Chee shows up only as a way to frame the story; there is none of the interaction between the two men as they come at a mystery in different ways and different stages of life that enlivened the early books. The action takes place after Chee is married, which (according to the other books) takes place 4-5 years after Leaphorn retired - but in this book, Leaphorn retired a few months ago. Even the plot itself falls apart once you stop and think about it: it relies on the idea that a man could spend several months moving around the Four Corners area without anyone noticing him except his accomplices, so that he could come back several years later with a different identity and no one would know. Given the emphasis placed on how people in sparsely-populated areas notice strangers, this seems improbable at best. Now that the plot lines are failing, there doesn't seem to be much reason to read any new novels in the series.