Like most sites of this nature, we keep getting book recommendation questions. Personally, I massively dislike these questions -- they're completely subjective and have almost nothing to do with our actual topic. "How do I do X in Unix" is a question best answered by Unix people; "what book teaches me about X" is a question best answered by a librarian. They also tend to end with my #1 indicator of a subjective question, "1 recommendation per answer please"
I almost closed the latest example, but we've clearly let people get away with them in the past, so I wanted to at least ask for opinions. Should these kinds of questions be on-topic here?