Without too much thought, I'd say
Robert Heinlein's Citizen of the Galaxy
TH White's The Once and Future King
Colin Wilson's Origins of the Sexual Impulse
Larry Gonicks's Cartoon History of the Universe
Alton Brown's Good Eats
I could be persuaded to change my mind about which Heinlein (maybe The Moon is a Harsh Mistress instead), which Colin Wilson (maybe An Introduction to Phenomenological Existentialism instead), and which Gonick (maybe Cartoon History of the New World instead), and for a food book I might go with Pat Chapman's Vegetarian Curry bible instead, in a different mood.
I also enjoyed The Moon is a Harsh Mistress. Never read Citizen of the Galaxy. I have now added another book to my growing list.