The Complete Father Brown...G. K. Chesterton...Penguin
Thirteen Detectives...G. K. Chesterton...Penguin
The Annotated Innocence Of Father Brown...G. K. Chesterton, ed. Martin Gardner...Dover
The Flying Inn...G. K. Chesterton...Dover
Four Faultless Felons...G. K. Chesterton...Dover
The Ball and the Cross...G. K. Chesterton...Dover
The Napoleon of Notting Hill...G. K. Chesterton...Dover
The Paradoxes of Mr. Pond...G. K. Chesterton...Dover
Manalive...G. K. Chesterton...Dover
Saint Thomas Aquinas: The Dumb Ox...G. K. Chesterton...Image/Doubleday
Orthodoxy...G. K. Chesterton...Image/Doubleday
Father Brown, the simple-seeming priest who solves mysteries by his experience and insights in the ways of the human heart rather than by clues like footprints and tobacco ash, is arguably GKC's most famous creation. He was portrayed by Alec Guinness in the 1950's movie Father Brown (aka The Detective), and has appeared in the PBS series Mystery. Father Brown identifies the criminal by realizing that he is no monster of mystery, but doing something that any man might do, that he might do, but for the grace of God that has spared him the circumstances. He is somewhat unique in the annals of crime fiction in that he not only discovers the criminal but offers him a way out of the labyrinth that he has lost himself in.
There is a movie adaptation of Manalive in the works (it has been shot, and is now in editing). It was produced by Dale Ahlquist, who writes and presents the show G. K. Chesterton: Apostle of Common Sense. The production cost was a mere $100,000, and what I can see of it looks rather amateurish, but Manalive is one of GKC's best books, and I certainly hope for the best for the finished project. You can take a look here: http://manalivethemovie.com/.
And I would like to state here my admiration of Dover book editions, both for their reprinting of classic and obscure titles and for their sturdy covers and binding.