Older editions of which books were better than the new ones?

$\begingroup$ This kind of thing is very subjective, but in my opinion the third edition of Computability and Logic by Boolos and Jeffrey is better than the fourth, at least from the point of view of someone interested in the advanced topics (as opposed to a student encountering the material for the first time). Some of the more interesting advanced topics were cut from the fourth edition. ... Read full article.