•Why it earns a slot
The book that coined 'God is dead' and the Superman, written as scripture-parody rather than argument, and one of the most quoted and most misread works in modern philosophy.
Nietzsche's Zarathustra descends from ten years of mountain solitude to teach humanity a replacement for the God he declares dead: the Superman (Ubermensch), a figure who creates his own values instead of inheriting them. Written as prophetic verse rather than argument, the book delivers its philosophy through parable, and its opening scenes contain nearly every idea Nietzsche is famous for.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.