I'd thought that Usula K. Le Guin's "The Ones Who Walk Away from Omelas" might have been an exception, but though it's had nine submissions, it's only ever earned single-digit votes, and a single comment:

<https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...>

Far more success in comments:

<https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...>

(I thought I might have first encountered it here, though it might have appeared elsewhere.)

Harlan Ellison's "I have no mouth and I must scream" has had some success: <https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...>

Marshall Brain's "Manna: Two Views of Humanity's Future" (2003) was what I'd had in mind when finding the Ellison story, but it's also had little success:

<https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...>

Cory Doctorow's Little Brother by comparison did well: <https://news.ycombinator.com/item?id=6390441>. Though still hardly spectacularly.

E.M. Forster's "The Machine Stops" has seen both multiple submissions and comparatively decent discussion: <https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...>

(Searching specifically for fiction is something of a challenge, I'm trying a few different queries as they occur to me.)

I suspect both length and copyright limitations work against fiction submissions generally.