I'd like to nominate The Case of the Velvet Claws
by Erle Stanley Gardner. If all you know of Perry Mason is what you've seen on TV, you're in for a shock. This is the first Perry Mason story, and in those early days he was quite different from the later books, written by Gardner after his fellow attorneys criticized him for writing about a lawyer who played so fast and loose with the rules. Unfortunately the ebook is only available from Amazon
as far as I can tell, although there is a 1½ hour Radio Dramatization at Audible
Thanks to a bungled robbery at a fancy hotel, the already-married Eva Griffin has been caught in the company of a prominent congressman. To protect the politico, Eva's ready to pay the editor of a sleazy tabloid his hush money. But Perry Mason has other plans. He tracks down the phantom fat cat who secretly runs the blackmailing tabloid -- only to discover a shocking scoop.
By the time Mason's comely client finally comes clean, her husband has taken a bullet in the heart. Now Perry Mason has two choices: represent the cunning widow in her wrangle for the dead man's money -- or take the rap for murder.