Thanks for a really interesting and insightful article. For what it's worth, Tim's book 'Frank Herbert' was quite influential in my life. Firstly, for helping me understand many aspects of the deeply influential Dune books. And secondly for waking up to the value of that kind of literary analysis, a whole genre of writing I had never seriously considered before.
For me, the most influential books have undoubtably been Patrick O'Brian's wonderful 20-book Aubrey/Maturin series. Starting with Master and Commander, and especially picking up with Post Captain, I've been reading and rereading these books since high school, and often reflect book on different situations and characters from the book. Sometimes I wonder how much of my personality has come from the books - certainly a lot of my daily expressions have.
Godel, Escher, Bach was another deeply, deeply influential book for me, for reasons that are probably obvious to anyone who has read it. Really, really mind-expanding, had quite an impact on my career development as well.
For anyone interested in this kind of discussion of culture and influences from books, you might want to check out a site called OurInfluences.com, that is all about this kind of discussion. It's not very big at present, but I really enjoy this kind of book talk, and would like to see it expand.