An updated list following some great suggestions from screenwriters of books that they’ve found particularly useful.
Poetics by Aristotle
The Hero with a Thousand Faces by Joseph Campbell
The Writer’s Journey: Mythic Structure for Writers by Christopher Vogler
Screenplay: The Foundations of Screenwriting by Syd Field
Story by Robert McKee
Save the Cat! by Blake Snyder
Writing Movies for Fun and Profit by Thomas Lennon & Robert Ben Garant
The Complete Book of Scriptwriting by J Michael Straczynski
Making A Good Script Great by Linda Seger
Into The Woods: A Five Act Journey Into Story by John Yorke
The 21st Century Screenplay by Linda Aronson
The Art of Dramatic Writing by Lajos Egri
The Anatomy of Story by John Truby
Essentials of Screenwriting by Richard Walter
Inside Story by Dara Marks
Adventures in the Screen Trade by William Goldman
The Tools of Screenwriting by Howard & Mabley
Writing Screenplays That Sell by Michael Hague
Psychology for Screenwriters by William Indick
The Soul of Screenwriting by Keith Cunningham
On Filmmaking by Alexander Mackendrick (about directing but with great sections on screenwriting)
Alternative Scriptwriting by Ken Dancyger & Jeff Rush
Doctor Who: The Writer’s Tale: The Final Chapeter by Russell T Davies and Benjamin Cook (an insight into the creative processes and pressures of showrunning)
The Insider’s Guide to Writing for Television by Julian Friedmann and Christopher Walker (UK focused)
Writing Television Drama by Nicholas Gibbs (UK focused)
Happy reading!
