If you want smaller, quicker payoffs (but in no way cheaper!), consider the anthologies of short stories by Ted Chiang. Most of them are 15-45 minutes to read, with a couple longer (1-2 hours). I've read both "Stories of Your Life and Others" and "Exhalation" in the last month and I turned to my wife and said "that story just blew my mind" for probably 75% of the stories. You can find a few online. Here is a very sho…
All of his stories are good though.
I’d recommend True Names by Vernor Vinge and After Life by Simon Funk if you like Ted Chiang: https://sifter.org/~simon/AfterLife/