I think the Father Brown story The Blue Cross was one of the very first of Chesterton's things that I read. This was in a collection published by Wordsworth, containing just a handful of the stories, and I think the editor had a particular liking for the more grotesque and borderline disturbing of the stories, because I came away thinking that they were strange and a bit icky. Later we got a Complete Father Brown and I made the acquaintance of some of the more congenial stories (The Sins of Prince Saradine is a favourite, and I love The Scandal of Father Brown), but Father Brown remained my least favourite of Chesterton's strange detectives.
And although Father Brown is by far the most famous (the paperback cover of my mother's Complete Father Brown calls him THE HIGH PRIEST OF CRIME!), he is very much in the tradition of Chesterton's other detectives - Basil Grant, Gabriel Gale, and Mr Pond. I think I have mentioned what each of these characters is intended to represent: Basil Grant, the anti-Sherlock Holmes, demonstrates that facts never point to a single solution; Mr Pond, that life is full of startling paradoxes; Gabriel Gale, that sanity means seizing with gratitude the gifts of heaven and that madness means ingratitude, autonomy, and self-determination; and as for Father Brown, he demonstrates the advantage that Christian faith and poetry gives to the student of human nature.
This is well demonstrated in the volume titled The Secret of Father Brown. As the book begins, Father Brown--quiet, apparently idiotic, yet somehow so keenly in tune with human nature that he is able to solve dozens of baffling crimes when he's not carrying out his duties as a Roman priest--attempts to explain the secret of his success to an acquaintance. As he does so, his mind roams back to eight of the cases that he's solved. A revolutionary poet prosecuted by a respectable barrister for the murder of a well-known judge. The uncanny disappearance of a priceless curio, apparently through Eastern magic. A blackmail attempt quite unlike any other, and an attempted revenge with deadly consequences...
The story I found most interesting, however, was The Actor and the Alibi. A beautiful intellectual actress married to a director of pantomimes and vaudeville bears her trials uncomplainingly. The conclusion isn't too difficult to see coming (I'm trying not to give it away), but things aren't what they seem in this miniature study of the politics of the sexes.
This was an excellent read--like all of Chesterton's works--built around the truth that all men are evil, and that there is redemption.