I've long been a fan of hardboiled detective stories, whether in fiction, games or movies. Dan Marlowe is probably high among the ranks of long forgotten noir authors. I discovered him after a reference by Stephen King in his Hardcase Crime original The Colorado Kid. Marlowe wrote over 40 books in his career of almost 40 years.
I read Marlowe's book The Name of the Game is Death on my Kindle and was immediately hooked. His style is certainly gritty, but it's also gripping. He's not necessarily writing about good guys, either. His characters can be pretty nasty, but they are not completely without principles. Marlowe worked as an office manager, bookkeeper, PR agent, salesman, and a gambler before settling in on his career as an author. He also befriended some pretty unsavory characters including convicted bankrobber-turned-author Al Nussbaum. In later years, Marlowe actually suffered from one of the biggest noir tropes ever: he had a serious case of Amnesia.
Many of Marlowe's books have been reissued on the Kindle for around $3, so it's well worth picking up a few. Hardcore noir fans may also enjoy a recent biography about the life of Dan Marlowe called Gunshots in Another Room by Charles Kelly.