I nominate
Boston Blackie by Jack Boyle. I always enjoyed the radio series about the jewel thief turned detective, and listening to his run-ins with the police who are never fully persuaded his reform is genuine. This book contains 28 chapters, and not having yet read it, I don't know if they're stand-alone short stories or an actual novel. Wikipedia says "Boyle's stories were collected in the book Boston Blackie (1919), which was reprinted in 1979 by Gregg Press," so I am assuming this 2008 Pulpville Press reprint is actually a collection of short stories. At any rate, it should be fun. Boston Blackie was one of the greats.