My friend Glen has lurched back into reading Sci Fi. This makes me immeasurably happy.
Of the genres, Sci Fi and Fantasy (or Speculative Fiction, as I believe it called nowadays) are the ones that most resonated with me growing up. I was a reader, and outside of history what I read was Science Fiction and Fantasy.
I drifted away from it largely in the late 1980's due to a combination of factors: a sense that there was less time to read and the fact that (in my opinion) the stories were not as well written.
Fiction is always to some extent a reflection of the age in which it is written because the writers exist in that age. Thus, for example, Andre Norton's starships of the future always looked like rockets from the 1950's (a delightful anachronism read through today's eyes). But well written fiction does not substitute the culture and beliefs of the age for a well written story; a story which is perhaps "socially aware" but poorly written is a poorly written story. Additionally (from the prudish side of me), the substitution of sex scenes for well written prose and hinting at instead of blatantly stating it is, well, in poor taste in my world.
I have written here about books that I re-read on an annual basis (some of which are sci fi and fantasy). To be a little more helpful, I thought I would list some of my favorite authors to give Glen a boost:
H. Beam Piper (Henry Beam Piper): Works largely published in the 1950's and 1960's. Space Viking is one of my all around favorite books on the application of history to the future. Other notable works of his I have read and recommend are Four Day Planet and A Planet for Texans and Fuzzy Sapiens. I have not read his Paratime series but assume it is up to the same standard.
Andre Norton: I have been reading Andre Norton for over 40 years. She was a very prolific writer with numerous books under her belt (I easily have 30+ and I have not scratched the surface). Dark Piper is one I re-read every year. Recommended: The First five books of the Witch World Series (they get a bit silly after that), The Stars Are Ours and Star Born (connected series), Daybreak: 2250 AD (a very good introductory "End of the World" novel), Night With No Stars, Star Rangers, Operation Time Search, Knave of Dreams - these are my favorites, but almost anything of hers will be enjoyable.
Robert Heinlein: I have a conflicted relationship with Heinlein. Some of his I really liked, some have not stuck with me. Favorites: Starship Troopers, The Moon Is A Harsh Mistress.
Robert E. Howard: The genesis from which most Sword and Sorcery sprang. His Conan stories are the best known (they were organized in the 1970's into an 11 volume series), but some of his lesser known heroes - Kull of Atlantis, Solomon Kane, Cormac Mac Art - are also worth a read.
Edgar Rice Burroughs: As Howard set the bar for Sword and Sorcery, Burroughs set the bar for "Earthman transported to a strange new society and has to make his way in it". John Carter is his arguably most famous character (outside of Tarzan, of course, who I never got into), but Carson of Venus and David Innes of Pellucidar (Hollow Earth) are also enjoyable. For all of these series, the latter books are exceeded by the earlier parts of the series.
Elizabeth Boyer: Elizabeth Boyer was a 1980's and 1990's author that wrote books based in a Nordic World; while the Nordic Gods never appear, there are other characters of Nordic mythology: Alfar (Elves), Dverger (Dwarves), Nisses, Barrow Wights, Trolls. Her first four or five books were all stand alone - The Wizard and the Warlord, The Sword and the Satchel, The Thrall and the Dragon's Heart, The Elves and the Otterskin. Her last set of books in this genre (before she apparently fell out of favor and disappeared) was a four part series. The first two, The Troll's Grindstone and The Curse of Slagfid, are the better of the two.
J.R.R. Tolkien: Tolkien is hit or miss for people; you either like saga sorts of tales or you do not. The Triology The Lord of The Rings is his most famous (the books are so much richer than the movies), but The Hobbit and The Silmarillion (which is even more of a saga based story that LOTR) are also worth a read.
Jerry Pournelle: I accidentally found Pournelle in the early 1980's with Birth of Fire, a book about colonization and creating a free society on Mars. I loved the books but never followed up with him until years later (sadly, he died within the last two years; I could have followed an actual living author). His short stories captured in the titles High Justice and Exiles to Glory capture the transition of Earth into an solar system empire. His cycle of books Falkenberg's Legion, Go Tell The Spartans, and Prince of Sparta are a lovely historical review cleverly hidden as a science fiction novel of how civilizations fall and are rebuilt. He also cowrote with Larry Niven; Footfall and Lucifier's Hammer both (in their own way) discuss the end of civilization.
David Drake: Drake, like Heinlein, is someone I have a conflicted relationship with. His The Forlorn Hope is a masterful retelling of Xenophon's Anabasis, or the retreat of the 10,000 Greeks through Persia (and one of those books I wish there was a sequel to because the characters were so compelling). His Hammer's Slammers were gritty, but less appealing as the frequency of swear words is a bit high for me.
I have others, but those are the big ones on my list. What Sci Fi or Fantasy books could others recommend?