I have created a community wiki question to encourage/enable users to share the books or paper from cognitive science that you think is most important for others to read and know about. Please just give one suggestion per answer and please make sure that you explain why it is important that people understand this reading and what it explains.
Note that you can suggest more several pieces of content if you think that they are all equally essential but this is generally discouraged.
I note that a previous question, which I have voted to reopen, asked for the must know papers of cognitive science and was closed for being too broad. If that policy of closing these sorts of "polls" remains in place then I am happy to remove or modify my question.
However, I would suggest that the question be left open as I have seen similar questions (1, 2) being very well received on other stackexchange forums and attracting considerable interest and engagement.
While some of these question have since been closed, I oppose that policy as I accord with the view from here, that "'must read books' questions are pretty much my favourite part of every stackexchange site – Damon Mar 9 '11 at 17:48"