* AdaptationDisplacement: The TV series is much more famous than the series of novels it was originally based on. It's also markedly different from the original series of novels. In the books, Murdoch is much more of a DeadpanSnarker and is outright contemptuous of Brackenreid, and solves his cases through legwork and talking to people rather than any form of science. Inspector Brackenreid is depicted as an incompetent drunk who's also bigoted against the Catholic Murdoch. George Crabtree is described as having a large build and is a married father of five.
* EnsembleDarkhorse: There are many fans who are quite fond of Henry Higgins, and would very much like to see his character become part of the main cast.
* FoeYay: Some fangirls began to ship Murdoch and James Gillies together after [[spoiler: the latter kisses the former on the mouth for a full three seconds in "Midnight Train to Kingston."]]
* HolyShitQuotient: Viewers all across the board were completely stunned when [[spoiler:Gillies kisses Murdoch rather passionately in "Midnight Train to Kingston"]]; ''no one'' saw that coming!
* TheWoobie: Whenever Murdoch breaks down and is NotSoStoic, especially when Julia told him about [[spoiler:her abortion and that it left her barren]] and implied that she wanted to break up their relationship.
* WhatAnIdiot: It's understandable that James Pendrick doesn't think much of Thomas Edison, given that the latter has been hounding him on suspicion that he's violating Edison's film technology patents. However, when you're an aspiring film director, it's probably not a good idea to turn down a job offer from the man who owns just about every movie screen in the United States, much less call him a "scoundrel" to his face.