The Baroque Cycle - Neal Stephenson - It was 3000+ pages all told, and I LOVED it. His writing has always enthralled me, and I was hooked from the start
Every Discworld Novel - Terry Pratchett - Not much can be said that hasn't already been said a million times over. If you haven't read them yet, start now
The Theory of Poker - David Sklansky - Helped out my poker game tremendously. I'm much more ev+ now
I can see that being an issue. I'm in the same habit with LOTR, ASOIAF and Harry Potter, reading each series once every two years or so, and it crushes my ability to read a lot of new books. I've avoided rereading Discworld so far because I know that it will never be as magical as the first read through.
But oh god, Baroque Cycle was unparalleled from a character-building perspective. I loved every second of it.
Every Discworld Novel - Terry Pratchett - Not much can be said that hasn't already been said a million times over. If you haven't read them yet, start now
The Theory of Poker - David Sklansky - Helped out my poker game tremendously. I'm much more ev+ now