The Cask of Amontillado is great for that. And the classic poem The Raven describes existential dread so well.

I found with King the scarier aspects were the more mundane and psychological parts of his writing. I also found in some cases the adaptations to be better in some ways -- The Shawshank Redemption adaptation is great. And the poem in the TV adaptation of The Tommy Knockers felt more impactful than the one in the book.

Poe's genius lies in the fact that his stories covered almost all genres of fiction. He had an incredibly sharp (though disturbed) mind.

In fact many have stated that he is the "Father of Detective Fiction" because of his creation of Auguste Dupin who became a template for subsequent writers, most famously Arthur Conan Doyle and his Sherlock Holmes.

Many of his writings are essays and observations which are hard to classify but nevertheless insightful. A few examples;

1) His essay on the scams of his day titled “Diddling Considered as One of the Exact Sciences” is a fun read - https://www.eapoe.org/works/tales/diddlnga.htm

2) His story "Some Words with a Mummy" (the mummy's name is "Count Allamistakeo") is a satire on the advances of his times.

3) His story "The Man of the Crowd" is just a series of observations and hard to classify.

When you read Poe, you often don't know what to expect next!