Without looking at what I said last time.
1. Sirens of Titan, Vonnegut. Think I described Vonnegut as 'the elephant in the room' last time. He still is. Powerful stuff for an 8 (?) year old. An introduction to nihilism
2. The Whole Earth Catalog. That would be the 'Next Whole Earth Catalog', you always prefer your first, like Dr Whos. What brave new world that has such people (and stuff, so much stuff) in it.
Think those are the big 2, nothing else comes close.,
3. Player Piano, Vonnegut. A technocratic dystopia. The best. And yet... 'a just machine to make big decisions, programmed by fellows with compassion and vision'. Thesis, antithesis, synthesis?
4. Illuminatus. Some of the sexual politics has dated badly, but we kind of knew it would.
5. Cosmic Trigger vol 1 (or 'Cosmic Trigger' as it was then). Wilson's autobiography. An anarchist techno-utopian. Plays into the dialectic of 3.
6. The Science Fiction Encyclopeda, Nicholls and Clute - the first version of course, as with Dr Whos you always prefer your first.
7. Breakfast In The Ruins / Engines of the Night, Malzberg - the former is an expansion of the latter. The book which explains SF like no other.
8. Design and Evolution of C++, Stroustrup - to read this book is to understand where C++ comes from and, perhaps, forgive
Gets more difficult according to an obscure power law...
9. Let's say 'The Awk programming language', Aho, Weinberger and Kernighan. Clearly comes from a kinder, gentler age, but this slim book is the most literate of all programming books.
10. Oh, I don't know, Cryptonomicon