Artificial Superintelligence
I like Tim Urban's Wait But Why? site (tagline: new post every sometimes). But I thought his article on The AI Revolution - The Road to Superintelligence was dead wrong.
Vaguely at the back of my mind was that I ought to try to write some kind of rebuttal, but it would have taken a lot of time (which I don't have) to research the topic properly, and write it up.
So I was delighted to come across Superintelligence - The Idea That Eats Smart People which does a far better job than I ever could have done.
I recommend reading both of them.