There’s all sorts of stuff to suggest –
Isaac Asimov’s ‘Foundation’ series is definitely worth a look.
Seconded, though the first three are the best, and Asimov writes females pretty badly in all of them (but worse in the later books where he's making a conscious effort to include female characters and doing it so very, very badly).
There's always the
Stainless Steel Rat and various other books by Harry Harrison which are fun, although many of them are Sci Fi Parody.
If you like short stories which verge on poetry, then Ray Bradbury, although some of his longer works (
The Martian Chronicles (aka
The Silver Locusts in some editions) and
Fahrenheit 451 are definitive of the genre.
Also definitely John Wyndham (apart from
Web, which is awful) and Halo Jones.