Listening to Long Books

In the next couple days I should be wrapping up listening to War and Peace. The unabridged reading I'd found ran to about 60 hours, which covered two months of commuting. Though Tolstoy has his frustrations, I've been glad to get through War and Peace again, at a rather more leisurely pace than when reading it for college, and thus retaining more. And using the commute time to do it seems like an enjoyable way to pass time that would otherwise be spent listening to the news or some such.

I've been trying to decide what to listen to next. My criteria are basically:

- Sufficient length that the book fill most of a month (thus, at least 20 hours -- 1/3 the length of War and Peace)
- The sort of book that I feel like I ought to read or re-read, but am unlikely to find the time to get to any time soon
- I'm trying to avoid strictly fun-read books, of the sort I'd tear through by staying up late or reading all through a weekend, in that when in the past I've tried listening to that sort of page-turner-ish book, I've ended up ditching the audio book half way through and tearing through the rest in print where I can find out What Happens faster.
- Something that isn't such a prose masterwork (or something I'd want to flip around and take notes on) that I'd feel hampered by listening rather than reading.

Possibilities I've got in mind thus far are staying Russian by switching to Dostoevsky and listening to Crime and Punishment or The Idiot (both of which, I must confess, I've never read, though I read and loved Brothers Karamazov) or switching to Dickens and listening to Bleak House.

Does anyone have suggestions for other long books which might be suitable for listening? (At the rate of one a month, there should be plenty of room on the wish list.)