You might try some of Azimovs short stories. For a bit more meat you might try Frederik Pohls Hee Chee saga. Book 1 was great.
Books
Book reader community.
Not really sci-fi, but shirt and very good: Fictions/Ficciones and Labyrinths by Jorge Luis Borges. Also, Invisible Cities by Italo Calvino.
The Mistborn Trilogy (start with The Final Empire) by Brandon Sanderson is superb.
After that initial trilogy they are a massive struggle, but the first three are well worth reading.
I absolutely agree with your recommendation, but man if they're looking for something short, the mistborn series is the opposite lol
Naive Super. Not sci-fi, but a quick enjoyable read. I've read it 4 times now. Its just a fantastic simple book to get back into reading fiction.
There are some great suggestions here - I'm also adding to my reading list!
I almost exclusively read sci-fi, and my favourite author is Peter F. Hamilton. He has written some mind-bendingly good space opera, much of it spanning multiple novels.
His best work IMHO is a one-shot, standalone novel called Fallen Dragon. It's got rampant uber-captialism, space marines, geurilla warfare on colony worlds, and aliens. And a very satisfying conclusion that I didn't see coming.
Something not by one of the more well known authors I could recommend are the Indranan War trilogy and Farian War trilogy, by K. B. Wagers
Also, The Frontiers Saga series by Ryk Brown is fantastic, and I think getting close to 40 books by now
Its not scifi, but Thieves Emporium by Max Hernandez.
There's a lot of good stuff here but I have to throw Andromeda Strain and World War Z into the pot.
Read Everworld
@foofiepie continuing with sci-fi definitely check out the Monk & Robot series by Becky Chambers!
“A Psalm For the Wild Built” & “A Prayer For the Crown Shy”
Short & beautiful.
Roadside Picnic. Not too long, but phenomenal overall and told via first person.
John Scalzi's book are an easy read. Its a lightweight Sci fi though.
Old Man's War, and Starter Villain are the two of his books I've read and enjoyed.