a few that I can reliably reread and enjoy immensely every few year in no particular order
The Broken Sword - Poul Anderson
Three Hears Three Lions same
Midnight at the Well of Souls - Jack Chalker
The Warden Diamond series - chalker
The Dragon Never Sleeps - Glen Cook
Flamesong/The Man of Gold - MAR Barker
The Eyes of the Overworld - Jack Vance (anything by this author)
The New Sun series - Glen Wolfe
A Soldier in the Mist - Glen Wolfe (historical fiction/fantasy)
Armor - John Steakley
The Mote in God's Eye - Niven/Pournelle
Revelation Space - Alistair Reynolds (beware the bad 3rd book in this series)
The Compleat Enchanter series - De Camp/Pratt
The Gap Series - Stephen Donaldson
CJ Cherryh - most of the union/alliance-setting books.
Northworld trilogy David Drake (prose edda and other saga based-sf)
To Cross the Stars - Drake
Terrific List and welcome to Chrons.