I'm no stranger to the writings of H.P. Lovecraft. I've written my own works in his universe with the CTHULHU ARMAGEDDON series as well as participating in the TALES OF THE AL-AZIF collection. I've also been a fan of the Call of Cthulhu game, the Big C's inclusion in everything from video games to the Justice League cartoon, and many of the wonderful pastiches done by authors who enjoyed HPL's work.
HPL was a great believer in sharing his work and people like Robert E. Howard (Conan the Barbarian), Robert Bloch (Psycho), and Clark Ashton-Smith (Weird Tales) ran with them. Certainly, I'm not someone to complain given mine has a post-apocalypse Westerns.
Here is a collection of Lovecraft-inspired stories that do their own thing set in the Mythos. They aren't necessarily stories of cosmic dread and pulse pounding horror but play with the themes of the alien, nightmarish, and surreal. They're not in any particular order but spread out for you to pick those you might find intriguing.
I should note that this is by no means a complete list and I intend to revisit these recommendations later but this is a good collection of books I very much enjoyed on theme. I encountered some truly amazing HPL-inspired work and some truly godawful over the years. I should also note that these books explicitly deal with the Mythos rather than are simply inspired by the original Weird Fiction writer himself--or it would be almost entirely Stephen King.
15. Shadows over Baker Street by various
Combining Sherlock Holmes and H.P. Lovecraft's creations seems like a questionable fit. Sherlock Holmes is the triumph of the rationalist and just against a chaotic disorderly force. Cthulhu is the triumph of the irrational superstition over a rational delusion. Yet, not only did they make a video game about Sherlock Holmes investigating the Mythos but this anthology and a number of other series were created around the Great Detective encountering the Lord of R'lyeh's minions. "A Study in Emerald" by Neil Gaiman is the standout work here for the reasons that he explains in his introduction.
14. Shoggoths in Bloom by Elizabeth Bear
Shoggoths in Bloom is a collection more than an actual coherent narrative but its titular story remains one of the more interesting ones I've ever read in science fiction. There's a reason that it won the 2009 Hugo Award for Best Novelette. Paul Harding is a black college professor who has the opportunity to harness the power of the shoggoth race to annihilate the Third Reich. All he has to do is permanently take their free will away and he'll be able to solve most of the world's problems. I consider it a form of Anti-Lovecraft as humanity's own insignificance matters little in the moral choice over whether to harness inhuman forces.
13.Cthulhusattva: Tales of the Black Gnosis by various
Cthulhu is a figure who has since moved from the page to New Age occultism, albeit with the heavy tongue and cheek awareness that most people either use him as a metaphor for the supernatural or are deeply stupid. However, the metaphor of an all-seeing yet uncaring embodiment of extraterrestrial forces may not be a terrible one. Indeed, some people believe Lovecraft actually created the Big C as a stealth parody of Christianity. He is, after all, a dead yet living God that will return to destroy the world. A day for which his followers will rejoice and be transformed into immortal beings who live in his holy city no less. The authors here play with Mythos spirituality and create quite a few fascinating tales. Oh and the cover for this is the bomb.
12. The Call of Distant Shores by David Niall Wilson
David Niall Wilson is the former Horror Writer Association (HWA)'s chief, a multiple Stoker Award winner, and a guy who gave me my big break so I'm horribly biased in this recommendation. However, this collection of HPL-inspired fiction really appealed to me. It's an assemblage of eldritch stories and weirdness from multiple other publications over the years and I really enjoyed it. My favorite story being "Cockroach Suckers" that is what happens when redneck hustlers find magical power than your typical New England atheist scholar. I recommend the audiobook version of this over the book because the performance by Eric Dove is excellent.
11. Awoken by Serra Elisen (pen name)
Making fun of Twilight is low-hanging fruit and a craze that has long since died down anyway. However, this book was written with Elisa Hansen (Vampire Reviews), Lindsay Ellis (The Nostalgia Chick), and Antonella Insera (Nella) from the former Channel Awesome crowd as a the kind of parody that I am greatly fond of. Specifically, the kind that is both a good example of the fiction its parodying as well as a send-up. Young Adult romance fiction, now with eldritch abominations! Basically, the story is of a young teenage girl Andromeda Slate (which is a parody on the fact Andromeda was meant to be sacrificed to a sea monster), is in love with the teenage boy avatar of Cthulhu. He starts killing the people who annoy her and driving insane others, which only makes the attraction stronger. But is she worth not destroying the world?
10. The Ballad of Black Tom by Victor Lavalle
The Horror at Red Hook remains one of HPL's more controversial stories about how a New York Detective is horrified by a multicultural group of Lilith-worshipers operating together in a New York neighborhood. The Ballad of Black Tom is the story of how a young jazz musician has a very different perspective on the events. There's a lot of interesting bits about class, race relations, and authenticity (as a concept) that make the story come alive as you read it. Part of what made me fall in love is the fact that he's not even a very good jazz musician but pretty sure most of his customers have no idea of that outside of Harlem.
9. Summoned by Anne M. Pillsworth
The idea of a YA Cthulhu Mythos boy's adventure is only slightly less ridiculous than a YA romance novel like Awoken. Anna M. Pillsworth combines Harry Potter with the haunted witch country of HPL by having a young boy discover he is a descendant of one of the cursed bloodlines that dwell in haunted New England. His fishy friend and the girl he likes have their own connections to Lovecraft's mythos. I enjoyed both of the current stories released and hope the author (who reviews Cthulhu Mythos stories on the Tor website) creates more.
8. The Atrocity Archives by Charles Stross
I am intensely jealous of Charles Stross. I wrote the novel Esoterrorism because I figured combining spy fiction and monster hunting was a unique idea, only to find out The Laundry Files was already out and amazing. I like the early books a bit more than the later ones but the premise is Bob Howard fights the supernatural for the British government. However, instead of glamorous Bondian adventures, he's a more LeClere-esque civil servant. The world is full of Cthulhuean horrors with the clock ticking down to the End of All Things (Case Nightmare Green). They are incredibly funny and good for both urban fantasy, Cthulhu, as well as spy fiction fans.
7. 14 by Peter Clines
Peter Clines' Threshold series us a joy to read and the best one of them is definitely 14. Combining Lost, Silent Hill, the Cthulhu Mythos, and even a little bit of Scooby Doo--it is a damn shame this is not a movie already. I have nothing but praise for this book and own it in multiple formats. The premise is a man finds a ridiculously cheap apartment in a creepy but functional old building in Hollywood. One room in the building is marked off and our new tenant's curiosity gets the better of him. It gets even more Twilight Zone from there.
6. Cthulhu Attacks! by Sean Hoade (and Byron Craft later)
Cthulhu is always rising, ready to destroy the world, but rarely does he ever get to succeed in doing so. The exception being Into the Mouth of Madness, my own Cthulhu Armageddon series, and Cthulhu Attacks! by Sean Hoade. Cthulhu Attacks! follows a group of people in a The Stand-esque story about watching the end of the world from the front lines. Sadly, Sean Hoade suffered a severe medical impairment that prevented him from continuing the series. Thankfully, fellow Neo-Lovecraftian Byron Craft and he have since managed to get the second book out together. Both of them are solid fans and great writers who deserve all the support they can get.
5. Lovecraft Country by Matt Ruff
Lovecraft Country by Matt Ruff is a work that I absolutely adore and am so glad is getting an adaptation to HBO. The premise is that a family of black travel guide publishers (they make "green books" that basically tell motorists of color where to go so they're not harassed by white people) are invited to visit their white relatives in New England. Their white relatives turning out to be a bunch of evil sorcerers capable of summoning shoggoths and Elder Gods. It is an excellent work for readers of all races and provides an alternative look to some of HPL's fears.
4. Winter Tide by Ruthanna Emrys
Like Lovecraft Country or Shoggoths in Bloom, Winter Tide is a book that addresses racial issues in the context of HPL but goes a more fantastical route. The central conceit is that it turns out the Deep Ones were just a religious and ethnic minority the US Treasury Department rounded up into camps post the Innsmouth Raid. Good is bad and bad is good in this universe where the Deep Ones are mostly just fishy pagans. Nevertheless, Ruthanna has a deep knowledge of HPL's universe and makes use of them here. This book is best read after reading The Litany of Earth, available on either the Tor website or in Cthulhusattva.
3. The Trials of Obed Marsh by Matthew Davenport
Matthew Davenport remains an author that I discovered by accident but have since enjoyed the works of tremendously. I was subject to an internal debate to recommend either his Indiana Jones vs. the Mythos "Andrew Doran" books here or this but ultimately settled on this. The Trials of Obed Marsh are a memoir by the Innsmouth founder. Just how does one go from being an ordinary sea captain to pimping your wives and daughters to fish men for gold as well as committing human sacrifices in the name of Dagon? Find out here.
2. The Elder Ice by David Hambling
Quite possibly the best HPL pastiche that has been written. I admit a certain bias to David Hambling's books because I found out about Lovecraft through the roleplaying games. The Harry Stubbs series that begins with this novella is as close to a Call of Cthulhu game as you're going to find in a novel. Harry Stubb is a WW1 veteran, ex-boxer, and of a slightly criminal bent who just wants to get by in the 1920s. However, events keep moving him into the occult mysteries of the Mythos even as he manages to hold onto his sanity better than most because he doesn't understand what the hell is going on 9 times out of 10. The first book is extremely short but available with the second as Harry Stubbs volume one.
1.The Burrowers Beneath by Brian Lumley
It took awhile but we eventually reached what I think is the best (despite my love of The Elder Ice). The Burrowers Beneath is the first volume of the Titus Crow series, following a Sherlock Holmes-esque occultist who has dedicated himself to the destruction of the Mythos. Already different from even Lovecraft's more proactive heroes like Professor Armitage, Titus Crow's first adventure is his best. The sinister Cthonians remain one of the best non-HPL monsters and the war against them covers a book with dozens of articles, short-stories, and narratives woven into its ranks. I also recommend the prequel in The Compleat Crow. Simon Vance does a fantastic job on the audiobooks and they're the format I believe works best for these stories. There's also the fact Tor books and Brian Lumley have had some "issues" that explain why the ebooks are coverless.
I hope this will give the Lovecraft fans among you something to read! All of these books deserve more attention.