The Egg by Andy Weir http://www.galactanet.com/oneoff/theegg_mod.html

It was Excellent. Sometimes I feel the other way. I am the only human and everything else is made up.

I’m real

This one always stuck with me too.

"Winter Dreams" by Fitzgerald is pretty great. It changed my perspective on wealth and has in general stuck with me for a long time: https://public.wsu.edu/~campbelld/engl494/winterdreams.pdf

Funes the Memorious, by Borges. "About" a dude (Funes) suffering from an infinite memory, written in a non-fiction tone/style.

http://vigeland.caltech.edu/ist4/lectures/funes%20borges.pdf

Not sure about MOST thought-provoking, but "The Bookmaking Habits of Select Species" and "State Change" (both by Ken Liu) are two good ones I read recently and think a lot about.

I read a lot of good ones in school:

* Hills like White Elephants by Hemingway * A Good Man is Hard to Find by Flannery O'Connor * Harrison Bergeron by Vonnegut * Most Dangerous Game

I recommend "The Merchant and the Alchemist's Gate" by Ted Chiang! An excellent sci-fi story set in the past that explores themes of guilt and repentance.

Metamorphosis by Kafka

"Postpaid to Paradise" aka "Postmarked for Paradise" aka "The Marvelous Stamps from El Dorado", a short story by Robert Arthur.

"A Christmas Carol" by Charles Dickens.

"For sale, Baby shoes, Never worn."

Attributed to Hemingway, but he may have cribbed the idea from others...

"The Machine Stops" by Forster sent me for a loop back in high school.

"The last man alive was alone in a room. He locked the door."

The open boat by Stephen Crane is amazingly well written

"I have no mouth and I must scream"

The Stranger by Albert Camus