Harry Potter and the Goblet of Fire - J.K. Rowling, Mary GrandPré

This is one of those posts I can't say much about, except that I really didn't see it coming. Did you?

 

Honourable mention goes to Monstrous Regiment 

"On my honour, I am not a shouty man"...

(show spoiler)

and The Well of Ascension.

I remember finishing and absolutely cracking up that the noble, generous, selfless act is the one that releases a plague upon humanity. Heh.

(show spoiler)