Lindsay, you ask for reasons. I offer the following:
1. "The Anatomy of Human Destructiveness" by Erich Fromm
The greatest analysis of the human condition and its impulse to destruction that I know. This work should be a text book in schools.
2. "Labyrinths" by Jorge Luis Borges
Truly extraordinary convoluted tales suffused in mystery.
3. "Godel, Escher and Bach" by Douglas Hofstadter
A wholly remarkable analysis of the mathematical foundation of consciousness - including concepts of thought. Its difficult and esoteric nature is very much a mark of its quality.
4. "Dracula" by Bram Stoker
The greatest horror work ever.
5. "The Scar" by China Mieville
The best gothic novel I have ever read. Alas, this author's most recent work, 'Iron Council', is something of a disappointment.
I trust these brief paragraphs are OK.
LLEWELLYN