•Why it earns a slot
Why it earns a slot: it invented the survival-log as a literary form, Crusoe's compulsive tallying of goods, days, and moral debts to God is the template every deserted-island and disaster narrative since has copied.
A shipwrecked Englishman spends twenty-eight years alone on an island, and the book is less about survival than about the account he keeps of it.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.