I have really enjoyed reading this thread and (mostly) agreeing with the sentiments expressed.
I started my own Dickens journey when I moved back into my mothers house at age 22 for a short while. I found myself sleeping on a sofa bed in her study, next to the bookshelf. Not being able to sleep one night, I picked up Great Expectations for something to read, and have never looked back.
I have now read all of his full novels with the exception of Edwin Drood (I don't like starting a book that doesn't finish - I tried it with the Salmon of Doubt by Douglas Adams and couldn't bear not knowing what happened next). Most of them I have read at least twice and I have never read an author that has managed to pull at my heart strings so successfully or allowed me such an insight into a society that is, to a certain extent, alien to me.
I find it difficult to rank the books, as that depends on my state of mind at the time, but some of them stand out as what can only be described as "timeless classics" although I feel that moniker is applied too often to books that may not deserve it. Not the case for Dickens. So rather than rank them, here are a few of my thoughts on each one:
Pickwick Papers - possibly the one I found hardest to read. This is probably due to the fact that, as a first book, CD had yet to settle down into the consummate story teller that he was to become. Having said that, the characterisations of Sam Weller (and his father) still amuse me and the meeting of Pickwick with Alfred Jingle in debtors prison was genuinely emotional (especially when the book, up that point, had been obviously a comedy). This change of pace is something that CD does so very well.
Oliver Twist - Before reading this one you have to try and forget any and all screen adaptations that have been made, as none of them do justice to the book. Again, as an early work, the descriptive passages are not as well crafted as later books, but having said that, the description of London's underbelly give you an insight into what early Victorian life may have been like. The two "stand out" passages in the book are the murder of Nancy (the uncontrollable rage and then mental anguish that follow) and the mental collapse of Fagin in the condemned cell make up for some of the more weak characterisations (especially Oliver himself).
Nicholas Nickleby - I would say this is the first book where CD had settled down into his own style. Excellent characterisation and a masterful plot. Although the journey of Nicholas is the main thread of the book, I found myself more drawn to the story of Kate and the pure wickedness of Ralph. In this book we also see CDs ability to create secondary narratives that stand alone, but also support the main plot - in this case the fate of Lord Verisopht who finally stood up to a bully and charlatan for the honour of a defenceless young woman, only to pay the ultimate price.
The Old Curiosity Shop - the main story of Nell, although heart-breaking, was not what makes this a masterpiece (maybe a little too sentimental) even though I am used to a story with a less than happy ending (thinking of LOTR), but I think that Quilp is possibly the best villain in his books and the journey of Dick Swiveller is so satisfying it makes up for the weaker parts of the novel (I have actually spent time on the south bank of the Thames in London, trying to work out where Quilps yard was located).
Barnaby Rudge - I knew little about the anti-popery riots of the late 18th century, but it proves to be an excellent backdrop to this tale. CD highlights how easy it is to be swept up in something you don't really understand, as Barnaby is throughout the book. I would probably rank this in the bottom half of my list, but not really due to any weakness in the book itself, but just due to how strong the competition is from his later works.
Martin Chuzzlewit - I loved this one. The dastardly Pecksniff who is happy to sacrifice his own family for personal gain, the downfall of Jonas through greed, the descriptions of America which got CD into some trouble on reading tours (although, let's be fair, he doesn't exactly paint the English as paragons of virtue) and the satisfying ending all add up to an excellent read.
Dombey and Son - I found this the most heavy going of the books (although with some of the best characters - the perceived tension between Captain Cuttle and Mrs MacStinger and the innocence of Mr Toots). I think the reason for the heaviness is the pure misogyny of Dombey, especially against his own "perfect" daughter Florence (maybe having two daughters of my own - one called Florence - made this more infuriating).
David Copperfield - I won't repeat what others have said, but I totally agree that the first third and the last third of the book are excellent. I seemed to spend most of the middle shouting "what about Agnes?" at the page.
Bleak House - one of the two that are probably my favourites. I initially found the change of narration a little jarring, but soon you understand that it allowed CD to delve into emotions and feelings from Esther's point of view which he couldn't necessarily do when written in the third person. But the intelligent evil of Tulkinghorn and the deviousness of Smallweed stand out as some of his best characterisations. The story and plot are so well crafted that you really don't notice how long the book is while reading it.
Hard Times - Didn't really enjoy this as much as the others. There is nothing wrong with the plot or the characters, but for some reason it just didn't grab me.
Little Dorrit - this is the other one of my two favourites. Having worked with quite a lot of the UK public sector, the circumlocution office was immediately recognisable. The way in which we, as a nation, treated those who had fallen on hard times and the ingratitude and privilege of wealth (especially newly found wealth) is a stark reminder of the flaws within us all.
A Tale of Two Cities - Although not enormously historically accurate, this book, along with Barnaby Rudge, shines a bright light on the way human nature can be twisted and corrupted through external factors. The "terror" of late 18th century France must have ben truly horrific and this book does convey some of that horror and I am not too proud to admit that (although I knew what was coming) I found the final chapters very hard to read (due to the tears in my eyes). Not necessarily the bravery and sacrifice of Sydney Carton (although partly that) but mostly the confusion and despair of the seamstress on the tumbril - not sure why she is there but facing her fate with fortitude thanks to Sydney.
Great Expectations - this is where I came in. I wouldn't put this in my favourites list but the description of the cruelty and revenge of Miss Haversham, the way in which class defined who you were and who you could engage with is second to none in this book.
Our Mutual Friend - A close third in my favourites list and, for me, possibly the best plot. It has a little of everything - class distinction, destructive characters, greed and avarice, jealousy and betrayal. But also comedy - you can almost picture Silas Wegg and Mr Venus in the dark room, surrounded by stuffed animals and body parts.
So that about wraps it up - I had only intended to write a quick response, but once you get me started on Dickens, I find it difficult to stop.
As a final thought - Audible do have all of the unabridged reading of the books. I found it useful to read the book first, then listen to the Audible version (mainly to get past all of the long sentences and fractured clauses) then re-read the book. I would also very highly recommend the recent BBC adaptations of both Bleak House and Little Dorrit (and to a lesser extent Our Mutual Friend). They are quite long to watch, but the BBC do an excellent costume drama and they take enough time to tell the story properly.
Thanks for indulging me