Intellectual or stupid dumbass?

[sylvar]

Jodi said tonight that she doesn't think I'm as much of an intellectual as I used to be because I don't read nonfiction as much as I used to. (I do watch philosophy lectures on DVD as I fold laundry, I've been watching a four-hour series on the construction of skyscrapers, and I almost always have a book on tape -- although those have tended to be fiction since I've listened to many of the library's good NF audio already.)

So, anyone got any suggestions? I guess she didn't notice when I was trying to wrap my brain around Brian Greene's The Elegant Universe, but I do like expository science essays in the tradition of Asimov and Clarke. Maybe I should give Guns, Germs and Steel another try. What else would you recommend to someone who wants to read intellectual stuff that's interesting and well-written?