Nice list! For me personally, Ulysses is a good example of a book that's difficult and not worth the effort (and Finnegan's Wake even more so). I slogged through it as an undergrad student, only persisting out of vanity. From a 21st Century perspective, it's just not a fun read and many of its innovations have been so integrated into subsequent literature as to have lost their effect (for that reason, it's worth the effort for a student of the history of literature, but I'm not sure I'd recommend it to others). You articulate that innovation wonderfully - namely its effort to capture "every fragmented thought, distraction, aside, and absurdity that flit[s] through our minds in a single day." But I think Virginia Woolf and other modernists did that far more effectively without inflicting so much pain on the reader.