I didn't read OMF or LD; I know both are held in fairly high regard. I thought DC, Bleak House and Great Expectations were at the top of the (Uriah) heep, which is what people here told me were his best novels anyway. I'm glad I read the Martin Chuzzlewit America section but not the rest of the book; A Tale Of Two Cities had a powerful opening and ending and depiction of the mob but was poor in terms of exposition and I ended up basically agreeing with TonyV's cynicism towards it.
BH is his best crazy quilt of characters and a lot of the satire is hilarious. If it had a big weakness it's the main character; she was too saintly. This is a common Dickens criticism.
I gotta say I really don't remember what happened in The Pickwick Papers at *all*. Yipes.