… without necessarily going the whole hog of a novel, or who are looking for a taste of several different things:
The British Library recently published several Golden Age mystery short story anthologies, all edited by Martin Edwards, four of which exactly match the bingo squares created by Moonlight Reader and Obsidian Blue. They are:
Miraculous Mysteries: Locked-room murders and other impossible crimes
Capital Crimes: London mysteries
Murder at the Manor: Country house mysteries
Serpents in Eden: Rural / village / small town crimes — for the “Terror in a Small Town” square.
They’ve all been out just about long enough to hopefully be available via library loan (or ILL) — though I’ve been able to snatch used copies online at very reasonable prices, too.