I just got the 40th special edition Bluray along with the book. The book actually had more pages of reviews, comments, essays, discussions that have been printed over the years than the actual length of the book itself.

So I think this makes SK's best movie in part due to the subject matter, ie mind control, free will, State control over its subjects and of course the Nadsat language which we are "brainwashed" into learning just by watching the movie.

So while 2001 SO and a couple other SK movies were thought provoking nothing compares to CO.