I remember Ann McCaffrey and Ann Rice, but never heard of Garth Nix. The horror authors sound familiar, especially Herbert. I'll have to check those out as well.
Another one I devoured was the Gord the Rogue series by Gary Gygax. Novels by one of the head creators of D&D and AD&D are rather.....creative! 🙂👍
Garth Nix is a fairly new author, I'm pretty sure he wasn't around when I was growing up. He also targets an adolescent audience, so that could be why you've not come across him. I'd still recommended the Old Kingdom/Abhorsen series for adults if you like fantasy. I've hung onto that series.