Fiction:
That Hideous Strength & Till We Have Faces ~ CS Lewis
The Fellowship of the Ring & The Return of the King ~ Tolkien
Small Favor & Turncoat ~ Butcher
White Fang ~ London
The Shadow Rising ~ Jordan
Based on a True Story: A Memoir ~ Norm MacDonald
Leviathan Wakes ~ Corey
That's just the top of my head. I haven't 'read' the entire Expanse series so I haven't had time to process and reflect on which book I like most. I guess that's true for Butcher's unfinished series and Lewis's space trilogy, of which I've only read That Hideous Strength.
I kept trying to put non-fiction in the list, but managed to refrain. (MacDonald's memoir is definitely fiction)