This is a brilliant book. Back when I was in school, I used to borrow this book from the library during summer vacation, read it throughout the summer and return it in the autumn. For every year, I understood more and more :-) Mind, I was around 15-16 years old, so this was all new and exciting stuff. Now, several years later, I find that bits and pieces crop up in ordinary discussions - recursion, DNA/RNA mechanisms, fractals on a musical level, Zen philosophy,Number theory, AI and mind discussions - that I have long since gotten a sort-of grasp of, due to this book. This is also the book that led me to read "Zen and the art of motorcycle maintenance" (another necessary book). Nowadays, 10 years later, I keep two copies of GEB on my shelf, one in english and one in swedish. Everybody need at least one...but you won't get mine!
I guess I should comment on the way tha hofstadter manages to mae the most complicated subjects understandable, how he manages to find links and analogies in very interesting places, how one can read the book again and again and still find new things to ponder...But I won't. You need this book. Your brain need this book. If you haven't read it yet, Do.