As a reader, it was a very happy day when I discovered John D. MacDonald and his Travis McGee series. I did not want to pick one book to recommend, but to wholeheartedly endorse the series.
If you are unfamiliar with these books, Travis McGee is a man who lives on a houseboat in Florida and works only when his coffers run low and when his sense of justice is stirred. Individuals hire him to right a wrong. They have been harmed in some terrible way, and if McGee can remedy the situation, he gets to keep half of what he can get back. They are always very dangerous situations. It is a journey into a heart of darkness, written in beautiful poetic prose, where MacDonald never flinches from the evil that lurks in these situations. There are tremendously tragic scenes and moments of enormous heartbreak. There are instances of humor and love. There's a portrayal of a great friendship between Travis McGee and Meyer, his confidante who also lives on a boat who counsels, consoles, and listens to McGee. I think they are astonishingly great books.
When you read the books, it's quite evident that they were written in a different time. The last of these books came out in the mid-eighties. The first was published in 1964. A contemporary Travis McGee would most likely be less Bondsian in some of his attitudes. To me, that was just a pose of the time. The books stand up with a great deal of heart and soul. Just writing about it now makes me want to read all of these books again.