Of the stuff mentioned, I've got Les Miz, Moby Dick, and the two big Tolstoys on the to-read shelf, along with Neal Stephenson's huge Baroque trilogy, which hasn't been mentioned but would also fit this topic. I have Genji and the Paul Scott quartet in storage, meaning hopefully someday. I've read and can heartily recommend Dumas' complete Musketeers trilogy and Monte Cristo. I gave up on Don Quixote and Winter's Tale: the former because the humor was too broad and the situations too repetitive, and the latter because the writing was too precious, as if the author was too much in love with his own writing.
I'm currently reading a mammoth sci-fi trilogy: Night's Dawn by Peter F. Hamilton. Each of the three volumes is over 1000 pages. Despite the length, it's quite the page-turner. Next will be Alexandre Dumas' gigantic Marie Antoinette series, with books 2 & 3 roughly 800-1000 pages and books 1 & 4 running 1500-2000 each (in the unabridged editions). I'd meant to start that concurrently with the Night's Dawn trilogy, but both have so many characters that I'd never be able to keep them straight.

