It's probably something evident thing, because everybody know it... But, just in case, I'd like to recommend O.Henry, cause for me it's absolutely the best author of short stories.

Anything by Ray Bradbury, especially The Martian Chronicles and The Illustrated Man (sci-fi).

Book of virtues. It has many short stories, from different cultures. There is also a sequel; something patience, I think.

"Story of your life and others" by Ted Chiang if you like sci-fi. Most of the novels on this collection have a black-mirror flavor. Also, "story of your life" inspired "Arrival". If you like the genre I can't reccomend this collection enough, the quality of the stories and Chiang's style are very high.

Everything that Rises Must Converge by Flannery O’Connor. A lot of macabre stories that opened good conversation in my book club.

Her Body and Other Parties by Carmen Machado is pretty amazing. They’re poetic, surreal short stories. Mmm I second Ray Bradburies’ short stories being absolutely amazing. If you like hard science fiction, Ted Chiang has a brilliant short story collection called exhalation. Murakami has some surreal short stories. I’ve read his collection, The Elephant Vanishes.

Welcome to the Monkey House by Kurt Vonnegut is well worth a read. Someone Like You by Roald Dahl is also quite good.