Check out Elizabeth Moon--she's done fantasy (Deed of Paksennarion) and sci-fi(Remnant Population, the Heris Serrano books which start with Hunting Party, and then branch out with Once a Hero).
Also David Weber (Honor Harrington books, and others set in that universe, and he's written other stuff as well.)
Lois McMaster Bujold. Others have mentioned her--she's a fabulous author. On my short list of "if she wrote it, I'll read it. Period."
Isaac Asimov and Arthur C. Clarke. Classic sci-fi at it's best.
Ben Bova.
Anne McCaffrey has written some sci-fi as well as the more fantasy-type Pern books. Don't get me wrong--I loved the Pern books, especially the early ones.
Andre Norton. You might have to look in the kids section for a lot of her books, but adults like them too. They cross over well.
C.J. Cherryh. Lots of sci-fi--I haven't read a lot of her books but what I've read has been pretty good.
Alan Dean Foster. Tons of books--check out the Flinx books in particular, and those of the Commonwealth.
Peter Hamilton and James Hogan.
Vonda McIntyre. She did a whole series starting with Superluminal that was really good.
Sheri Tepper is also good. Add feminist to environmentalist.
Needless to say I'm a sci-fi/fantasy fan myself. I've gotten rather picky about fantasy in particular--Terry Brooks & Robert Jordan don't cut it. (Hope I haven't annoyed any fans!) I run more to Tolkien and Guy Gavriel Kay, and Bujold and MZB at her best. I could pontificate lots more but I'll spare everybody.
Erika
Also David Weber (Honor Harrington books, and others set in that universe, and he's written other stuff as well.)
Lois McMaster Bujold. Others have mentioned her--she's a fabulous author. On my short list of "if she wrote it, I'll read it. Period."
Isaac Asimov and Arthur C. Clarke. Classic sci-fi at it's best.
Ben Bova.
Anne McCaffrey has written some sci-fi as well as the more fantasy-type Pern books. Don't get me wrong--I loved the Pern books, especially the early ones.
Andre Norton. You might have to look in the kids section for a lot of her books, but adults like them too. They cross over well.
C.J. Cherryh. Lots of sci-fi--I haven't read a lot of her books but what I've read has been pretty good.
Alan Dean Foster. Tons of books--check out the Flinx books in particular, and those of the Commonwealth.
Peter Hamilton and James Hogan.
Vonda McIntyre. She did a whole series starting with Superluminal that was really good.
Sheri Tepper is also good. Add feminist to environmentalist.
Needless to say I'm a sci-fi/fantasy fan myself. I've gotten rather picky about fantasy in particular--Terry Brooks & Robert Jordan don't cut it. (Hope I haven't annoyed any fans!) I run more to Tolkien and Guy Gavriel Kay, and Bujold and MZB at her best. I could pontificate lots more but I'll spare everybody.
Erika