How could I have forgotten: A Tale of Two Cities by Charles Dickens. I have not read it, but as Pierre Bayard says in How to Talk about Books You Haven't Read (see prior post on this), I know the important things: the author, the setting of the French Revolution, the famous opening lines ("It was the best of times..."). A trip to Paris would be the PERFECT time to read the real thing. I guess this is the moment to mention Les Misérables by Victor Hugo as well.
Also, I did not mention Iréne Némirovsky's books, because I have not read them, but I would maybe try to get my hands on Suite Française to read for a trip.
I debated but did not include The Many Lives and Secret Stories of Josephine B, about Napoleon's creole empress, by Sandra Gulland, but I have decided to mention it after all - it is a reasonable piece of historical fiction about Paris.
PS I have written a post about what to see or read for a trip to New York with kids, and maybe I'll add a "travel reading" tag to make such lists easy to search.