The most ridiculous example is the 5th edition of "Learning Python" by Mark Lutz. It's supposed to be an introduction to the Python language and it's almost 1600 pages long. The 1st edition was less than 400, the 2nd was 550, the 3rd was 750 and the 4th around 1200 pages.

It's a very nice book, don't get me wrong, but I think it's intimidating for a beginner.