Updated list from me:
Category 1: Dickens' finest work, combining mature writing, exceptional characters and deep plots
Bleak House
Our Mutual Friend
Great Expectations
Category 2: Classic works, with great characters and highly memorable scenes, but flawed in some way
Dombey and Son (loss of a major character early on was a strange choice)
Hard Times (less 'Dickensian' than other books, otherwise great)
The Old Curiosity Shop (two story threads move apart for Nell's journey; but best Dickens villain perhaps)
David Copperfield (flabby middle is poorly paced, with a disjointed storyline; but first and last third are great)
Category 3: Lesser Dickens: good reads, and still recommended works, but not to be prioritised given their imperfections
Oliver Twist (coincidences abound; terrific characters but plot difficult to accept)
Nickolas Nickleby (somewhat light plot doesn't engage the reader as much as his best; lacks the eccentricity of his best works)
A Tale of Two Cities (less intertwined Dickensian plotting and less strong on character, but has its moments, certainly)
The Pickwick Papers (early style, with many deviations and inserted tales (not all great); but terrific characters and a good end)
11 read, 3½ to go; I'm still to read Barnaby Rudge, Martin Chuzzelwit, Little Dorrit and the ½, which is Edwin Drood.