I just completed all of Henning Mankell's Wallander novel and it is by far my favorite scando-mysteries series. The last in the series The Troubled Man refers to both the subject of inquiry as well as Kurt Wallander himself. Both plots are jam packed with great character development as well as plot twists but I was most moved by the older Wallander, as he learns the lessons of aging and contemplates his diminished health.
He is humbled as he reviews his life but he displays genuine vulnerability and courage in the way that he evaluates himself and takes responsibility for his flaws. Ultimately, as disappointing as some of his life has been, he stands tall in gratitude for the less than perfect but meaningful existence and helpful vocation as a detective he has lived.
As many have mentioned in this thread do not start with The Trouble Man but read at least a few prior volumes so you can really appreciate Kurt's development and his ultimate encouragement to his less than perfect readers.