If this were a poll,

[ZatarRufus]

Gödel, Escher, Bach by Hofstadter

This is one that I have and read in August of 2009. I find it interesting that both you and Kylearan choose it as a top priority. While I did enjoy it immensely, it is quite a bit over my head and I personally wouldn't take it as a third of my choices. I did underline about 5% of the text as I read and cross referenced the 'see figure x' references (p702 see 82 & I noted it was back on page 494).

The selections I made where based more on their ability to keep my mind occupied than to entertain me.

This would be my sole criterion as well. I'm thinking more along the lines of Newton's Principia for the Common Reader by S. Chandrasekhar for my mental gymnastics.

Book Suggestion Sub-Topic

For you (Pete) and kandrathe, I would suggest either The Book of Nothing (Vacuums, Voids, and the Latest Ideas about the Origins of the Universe) by John D. Barrow or The Theory of Laminated Spacetime by Barbara Dewey.