Fiction?

I used to read a lot.  Still do; just not as much as before.  Mostly fiction.  I have enough reality, thank you.

Every once in a while, I read a piece of fiction so real it suggests the author is not making up events but rather reporting on events that happened in an alternate universe or time line.  As much as I love Heinlein, Asimov and Clarke I never got that vibe from even their best works. But here are two that really seem "real" to me:

Frank Herbert's Dune.  But not the sequels.
Mary Stewart's Merlin books.  Well, the first three, anyway. And how!

I've read that Robert E. Howard actually said that he felt like he was transcribing an adventurer's tales when he wrote the Conan books.

Hmmmmm.