Don't know what sort of audio credits you mean, possibly related to Podiobooks. Most of my story listening of late has been more of a podcast thing, but I do remember liking Other People's Heroes. I don't remember if I got through How to Succeed In Evil as well, since I keep thinking more was added to it later. Either way, as far as books go, those are two ideas.
Now, if you don't mind something a bit more ongoing, there are various podcasts I've messed around with, though these tend to be horror oriented. I'll make sure to include the status of the podcast as well in this list:
Limetown (Complete) More Suspense/Thriller than Horror. A young reporter investigates the mystery of a company town whose entire population disappeared under mysterious circumstances. Highlights: A voice actor I'd swear was Bruce Campbell. "Don't try to run." Actual answers by the end.
Black Tapes (Ongoing) Horror themed. They just finished season 2. A podcaster's show on various odd professions winds up focusing on a man who debunks psychics and the paranormal, specifically on a set of cases that are as yet unsolved. Highlights: At least a few plausible non-supernatural explanations, even if the explainer in question could use a better bedside manor.
Archive 81 (Complete) Horror themed. An archivist finds out the tapes he's digitizing have a mystery to them... Highlights: an oddly enjoyable smarmy boss.
Small Town Horror (Ongoing) Horror themed. They just started season 2. A man returns to the hometown he left long ago and finds himself caught up in a mystery involving an urban legend he once participated in, and an abduction nobody believed him about. Highlights: the familiar feel of a man exploring an urban legend
Bright Sessions (Ongoing) Urban fantasy/sci fi themed. A psychiatrist (or therapist?) who specializes in unusual cases, aka people with telepathy, empathy, and time travel powers, records her ongoing sessions to help her patients cope with their powers. Highlights: Time traveling ain't all it's cracked up to be, and the budding romance of an empath.
Lore (Ongoing) Horror themed. The host examines a different set of horror folklore every episode to get a sense of what we find frightening about them while highlighting tales related to the subject. Vampires, changelings, evil dolls, insane asylums. Highlights: Another inspiration for Dracula, a look into the murder palace of Dr. H.H. Holmes, real Slender Man-sounding folklore related to an asylum, the lobotomobile, and a doll that likes to run around an empty house.
King Falls AM (Ongoing) A small town, late night radio program in some forested "tri-state area" that sounds a lot more natural and realistic than Welcome To Night Vale. Highlights include: The apparition of Abraham Lincoln, Jack-In-The-Box Jesus, old man Hershel Baumgartner's colorful cussing, sugar gliders, Creepy Carl, and Archie's Pomchi Palace.
Criminal (Ongoing) True Crime, not always focused on the grisly stuff. Various criminals and their crimes are examined. Highlights: a recipe courtesy of San Francisco's original pot brownie lady, and actually showing where innocent people were caught up in investigations.
The Jim Cornette Experience (Ongoing) Wrestling. You're not going to like this one unless you're a fan of the squared circle. Highlights: funny old wrestler stories, Jim Cornette
We're Alive (Ongoing) Horror-themed, Zombie (Fast, possibly living). This one's been going on for a few years, so there's a bit of an archive. It's pretty good quality, and picks up at the beginning of a "zombie" apocalypse. Highlights: A French accent, Datu the maintenance man, and an old man with a gun not afraid to quote Mad Max II at other survivors.
God Awful Movies (Ongoing) Movie Review Series. Three hosts (and sometimes a guest or two) examine religious propaganda movies from an atheist perspective. Highlights: The Lock-In, a found footage-style horror movie where a simple church lock-in goes horribly wrong when a group of high school seniors are stalked by... a demon-possessed nudie magazine. Not Making This Up.
The Truth (Ongoing) Fiction of various genres. The ones I've heard weren't really that much a matter of horror. They're more or less about making stories of various stripes for people's ears. I didn't care for them particularly, but I've been looking for scary stuff, mostly. Highlights: Don't Touch A Thing, Santa for President.
Pseudopod (Ongoing) Horror themed. I'm inclined to say this one didn't have any horror either. It's all about having a different horror story every episode, but the ones I listened to were pretty predictable and didn't creep me out at all. Dishonorable Mentions: The Connecting Door and Final Girl Theory. Especially The Connecting Door. I just couldn't believe somebody got paid for a story that stupid.
The Rogue's Gallery (Ongoing) Supervillain. I just started this one, so I don't know if this season is all there will be yet or not, but said season isn't done yet. Supervillains Freakuency and Fugitive Color have been given a deal after serving 1 year of each of their sentences. Now the pair must host a radio show trying to show people why it's a bad idea to turn to villainy. It gets better once the two start to sound different enough. Highlights: Velocirapture the preaching dinosaur, robbing the same store every week, "You mean we all this time we were talking, we could have escaped?!"