The Restaurant at the End of the Universe, aka the day Douglas Adams discovered cut and paste.
This book is actually something of a technical challenge given portions were hand written and cut and paste was actually somewhat new technology at least at the desktop. The book however addresses a number of the weaknesses of the second radio play, ditching the overdone shoe economy in favour of a more economical book and the result is definitely easier to read even if it’s not got a lot of additional material.
While this book is still not as accessible as the original it’s a lot of fun.
Plus you get the bonus of the stage play and game.