Ulysses, by James Joyce. It will change your whole conception of what language is and how it can be used. It’s not about the characters or plots; they are recycled from antiquity. It’s about the absolute mastery of interrelation between words and imagery. It is something that has a meaning entirely emergent of its’ own self referential structure, rather than what is being described , in a sense that is almost mathema…
Reader beware, this book can eat smart people. I've known multiple PhDs who, after reading Ulysses, could never get through a party without talking about it.
A friend once ended a party at his place by reading Finnegan's Wake out loud to get people to leave.