Kallocain

It's dated but should not be forgotten.

This book belongs in the same line of books as "Brave New World" and "1984". (It precedes the latter). The state is even more all-encompassing than in these two and thus, any kind of opposition has to form on a even more fundamental level - in private thoughts. This makes the book somewhat harder to get into than the others, but the points it makes are just as important.

Mostly recommended.