From time to time, one runs across slicing witticisms that are just too scathing to be ignored.  I've collected a few.  Note that, in most cases, I don't (necessarily) agree with the insult, but I am a fan of the mot juste.

• "Oh Benson, dear Benson, you are so mercifully free of the ravages of intelligence."
  -- Ultmate Evil, to a henchbeing, in the movie  Time Bandits .
  
  
• "He isn't right.  He isn't even wrong."
  -- Some famous physicist, whose name for the life of me I can't remember.  I also can't recall of whom he was speaking, or the context of the quote, or (I suspect) even the correct wording.

Gilroy's Pages : Quotables

(Quotables index) (an explanation for the image)
(UBIDUBIUM.NET)

Quotable Barbs, Insults, and Put-Downs