At Swim-Two-Birds by Flann O'Brien

An undergraduate in Dublin with a fondness for lying in bed, not attending lectures and drinking with his friends decides to write a book with 'three openings entirely dissimilar'. These three openings are the introductions of three apparently unconnected characters, who we later find out are actually the creations (maybe) of Dermot Trellis, an author of Westerns. But these characters have had enough of being forced to do what they're told. They hatch a scheme by which they drug the author, allowing them to pursue their own lives. This is probably one of the most ridiculous, funny and imaginative books I've ever read, and it's also tremendously emotionally perceptive. It questions the very idea of a 'character'; literary works are continually turned into a hall of mirrors in which the author sees himself and tries to manipulate characters to behave according to his logic, but they, not being him, rebel. Besides this, the novel satirises and twists literary genres, from Irish legends to the modernist novel. There's nonsense here worthy of Lewis Carroll and literary games galore. Sarcasm, wit, keen observation, and utter insanity. Boundaries between the author, the narrator, the reader, the character, human, animal, spirit, and basically anything and everything else are being continually broken down. This is metafiction with a vengeance and I am completely in awe. I had so much fun with this book, it was incredibly stimulating and hilarious to read.