#69: The seminal Godel, Escher, Bach by Douglas Hofstadter. Easy to see how this nerd-sniped a lot of people and steered the intelligence dialogue entire. https://en.wikipedia.org/wiki/Gödel,_Escher,_Bach
#70: Erikson's Deadhouse Gates, book two in the Malazan Book of the Fallen. So. Damn. Good. Even on my fourth (perhaps fifth?) encounter. Read the MBOTF, I beg you. https://en.wikipedia.org/wiki/Deadhouse_Gates