Foundation series is my favorite. Read the Robot and then the Empire series by Asimov which are all set in the same universe as Foundation. Not as good, but there will be some pleasant surprises.

Dune and sequels by Frank Herbert are the next logical option, with similarly large scope.

The Expanse series by James S.A. Corey is great, set in the solar system in the near future.

Andy Weir's Project Hail Mary and The Martian are super fun reads, technically fulfilling the "not on Earth" requirement. Both are about one person's overcoming great odds, so a very different brand of sci-fi.