Howard Phillips Lovecraft (August 20, 1890 – March 15, 1937) — known as H. P. Lovecraft — was an American author of horror, fantasy and science fiction, especially the subgenre known as weird fiction.
Lovecraft’s guiding aesthetic and philosophical principle was what he termed “cosmicism” or “cosmic horror”, the idea that life is incomprehensible to human minds and that the universe is fundamentally inimical to the interests of humankind. As such, his stories express a profound indifference to human beliefs and affairs. Lovecraft is the originator of the Cthulhu Mythos story cycle and the Necronomicon, a fictional magical textbook of rites and forbidden lore.
He was also a raging asshole. But he did write some awesome gothic horror.
Any story in which he is not being a raging racist is pretty much awesome. My fav is At The Mountains of Madness, where he is prevented from unleashing his hate of native peoples due to the setting being Antarctica.
(Actually my favourite is The Colour Out of Space, but Mountains of Madness is still awesome)