My dad loved the Horatio Hornblower novels--history with plot! Also any of the "Stephen Bury" novels (by Neil Stephenson and his father-in-law)--very good political thriller/near future stuff. Heck, he might even like "Zodiac".

I third(?) the World War Z book. I've been giving really-fucked-up protagonists a pass, lately, but I am re-enjoying the "Sookie Stackhouse" series. Though her Shakespeare series was just re-released, and that lead is messed up, and does grow over the series (mysteries).