Stainless Steel Rat series (Harrison - a bit juvenile, but fun)
Dune (Herbert)
The Moon is a Harsh Mistress (Heinlein)
Stranger in a Strange Land (Heinlein)
Starship Troopers (Heinlein)
A Scanner Darkly (Dick)
Do Androids Dream of Electric Sheep? (Dick)
The Hitchhiker's Guide to the Galaxy (Adams)
Childhood's End (Clarke)
Robot series (Asimov)
Bicentennial Man (Asimov)
Brave New World (Huxley)
I'd recommend Issac Asimov's short stories. The robot series for example: https://en.wikipedia.org/wiki/Robot_series. You can read a few of those in a sitting.
* Foundation Series / Robot Series / Empire Series
* The Gods Themselves