I agree with you about the humour - both Nicholas Nickleby and Pickwick Papers have some of the funniest passages I've ever read in my life! I don't think it's about social commentary - that's not so important for me in a book, but Little Dorrit and Bleak House are just packed with all sorts of good stuff - Little Dorrit especially has such a grand cast of characters, so humanely and lovingly drawn. I love David Copperfield, but not as much as these other three, but unfortunately I've forgotten why. Perhaps it might have ranked with Great Expectations if GE hadn't been my first Dickens novel, so first love.