Best Computer Books For The Smart

You'll remember last week, I asked for recommendations of the Best Websites for developers. This was a -great- thread and in the story, I mentioned that I was planning on doing the same regarding books this week. So here it is. What do you, the slashdot reader consider seminal works? What would you consider great introductions to technical topics? If you are interested, check it out... As part of this I'm looking for books on C, C++, Perl, Python, PHP , System Administration, anything...you name. As before I have opinions on great books, but I want to see what you think. Also, what do people think is a great introductory book for people new to linux.