These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment Of Funny: All of Drusilla Clack's narrative. Apparently even Collins thought so; he wrote those passages out during a very dark period in his life, and writing them out cheered him up enough to keep going.
Fair for Its Day: Although all of the protagonists describe the Hindu priests who have tracked the Moonstone down as exotic, frightening, and untrustworthy, Collins still presents their claim to the Moonstone as true and valid, and its eventual return to them is shown as the setting right of an old wrong.
Les Yay: There's a very strong connection between Rosanna Spearman and Limping Lucy. It seems especially pronounced on Lucy's side - she talks about how she and Rosanna were going to move to the city and "live like sisters," calls Rosanna "my darling".