Piranesi, Susanna Clarke. I didn't think I was interested in this at all, from the description I read of it, and then I loved it. Another case of what I think I want in books not being aligned with what I actually want, I guess. Anyways I don't want to say too much (this is definitely a puzzle-box book) but it is beautifully constructed and is the kind of thing that works in a bunch of different ways at once, plot and imagery and symbolism. (I will spare you my lit-class interpretations but I enjoyed making them.) Based on my own experience I recommend it even if you were dubious about what you've heard about it. Might appeal to fans of Byatt's Possession, or Stranger in Olondria. (Note: I feel obligated to say that unlike what you might expect of my age and general reading profile I haven't actually read Strange & Norrell, so I have no opinions about any comparisons there. (I was going to say I was one of the few sff fans who still hadn't and then I was like... except everyone *born since it came out* probably, yeesh, time.))