No.
Edward, Lord Dunsany was first. And heavily influenced Lovecraft, too boot.
Lovecraft is as good a horror writer as there has ever been. As is the case with Poe, all that ponderous prose just crawls under your skin after a while and decays there. Stephen King is Beatrix Potter by comparison.
The “Cthulhu mythos” really doesn’t exist; the supposed unity in Lovecraft’s work was something Derleth dreamed up. But Lovecraft did create a universe where the baddies are really creatures from another dimension, and not really supernatural at all. Or, to say it a different way, the supernatural becomes subject to its own (eldritch) natural laws. Personally, I think this is great existential stuff.
All that said, I’m not sure I’d want Lovecraft being considered literature. I’ve sat through lectures on Poe; professors manage, against cyclopian odds, to make him boring. I hate it when that happens.
Obligatory link to a fantastic Cthulu game
I finally caved in and bought Call of Cthulu and other short stories last year but didn’t finish it, it really didn’t grab me. I think I was expecting a consistent mythos and actual novels and what I got was a lot of imagery and short stories, which tend not to work for me.
Maybe I’ll give it a go again, I recall seeing either a Lovecraft or heavily Lovecraft inspired novel in the Sci-fi section whilst browsing recently. Any idea what that might be? It was a detective novel, I think.
I think HPL counts not just because of the Mythos (some of his best, like* Cool Air*, are not Mythos tales AFAICR), but also because of his central place in an entire genre, as editor, collaborator and sometimes just friend to other writers.
Lovecraft was uneven, but when he was on, he produced some great stories. I loved “The Color Out of Space,” and especially “The Rats in the Walls,” where he goes into this long tedious history of the place but which pays off brilliantly in the end.
Well, there’s this way:
I made the mistake of readingThe Color out of Space late one night. I had trouble sleeping… 
Absolutely one of the creepiest things I’ve ever read. The way that the color just makes it too hard for you to even think about running, once it gets into you - that sort of parasitic ennui is just deeply chilling, somehow.
Lovecraft at his best (The Shadow out of Time, The Hound, The Colour Out of Space) was great.
But he was very much a one-trick pony, and many of his stories are laughable in the amount of thesaurus-scraping he does in search of synonyms for “grotesque.”
I find it strange that Lovecraft has become more celebrated than Robert E. Howard, who was an altogether superior writer, even in Lovecraft’s home genre. Sadly, he’s mostly remembered for Conan, who is mostly remembered for the Schwarzenegger movie of the early 80s.
Read Pigeons from Hell sometime, if you get the chance. That’s Howard in “Lovecraft” mode and, despite the title that seems comical to a modern audience, is actually a pretty horrifying short story.
Or actually read a Conan book if you haven’t, as the movie doesn’t really do the character justice. Or Solomon Kane, or Kull …
I’ve always believed the title was imposed on Howard by an editor.
And Howard could do more than that.
His Westerns are among the best I’ve ever read. And he could do humor/comedy, too.
Check this out–
Full text. You’re right, that’s a pretty good one.