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.
Isobel Crawley in the 2012 Christmas special. Interpretation 1: She literally had no idea what Dr Clarkson was getting at. Interpretation 2: She knew exactly what Dr Clarkson was getting at, but pretended she didn't because she didn't want to upset the status quo and/or she's really not interested. Which of these is true remains to be seen.
Did Thomas hate the nanny's attitude? Or did he get rid of her because he was genuinely concerned for the children (especially baby Sybbie)?
Did Rose really care about Jack, or was it all just about shocking her mother?
Given Elizabeth McGovern's spacey performance in the last few episodes of season 4, some fans suspect Cora has turned to drugs to dull the pain of losing Sybil.
Series 3 is Flame War-inducing; Series 2 at least had the excuse of World War I and the Spanish flu for all the added drama and character deaths, but Series 3 is supposed to be a return to normalcy - and yet, it's even more like a Soap Opera, although not all of it's the writers' fault (as with the two characters who were McLeaned).
Sybil's death in Series 3. To say that the fandom was pissed is an understatement.
Matthew's death has caused more of an outrage.
Anna's horrific rape in season 4. It's been accused of being a sleazy, manipulative writing trick designed purely to shock the audience with little consideration of what would come afterward, considering the fallout focuses much more on Bates than Anna.
Canon Sue: John Bates. He is a mix of Purity Sue and Sympathetic Sue. Every other character who has interacted with Bates is either in love with him beyond reason or turns into an archenemy with little to no provocation. He is regarded as a saint with most and acts the role frequently refusing to do anything that will hurt his enemies (who are going out of their way to hurt him). And if there is something that can go wrong for him, it will go wrong, even when it makes no sense and has the characters who are going out of their way to cause problems for him look cartoonish.
Saturday Night Live's surprisingly accurate summary of the show: "There's a MILF and a dad and they've got three daughters named Hot (Mary), Way Hot (Sybil), and The Other One (Edith). And they all hang out with this old lady that looks like a chicken. We hated her at first, but then we got high and she made us crack up![...] There's also a whole bunch of tuxedo people who live in the basement and their lives suck! Get this: They always have to stand up at the same time. Their names are: Nice Guy (Bates), Mean Guy (Thomas), Mouse Girl (Daisy), and Super Bitch (O'Brien)."
Ensemble Darkhorse: John Bates. And chauffeur Tom Branson, who has a surprisingly large place in the fandom considering that he showed up halfway through the first series and was never considered a regular character until series 3. But probably the most popular character is the Dowager Countess, for being one of the all-time champion Deadpan Snarkers.
Epileptic Trees: Not quite as erratic as most, but when Rob James-Collier showed up to an event with a shaved head, despite other actors saying they were only about halfway through filming for Series 4, fans started letting the in-show speculation fly. The two most popular seem to be either he's being somehow written off (or, considering Julian Fellows's track record, killed off,) or that Thomas was going to be in jail for part of Series 4 (which, considering how Series 3 ended, isn't entirely impossible.)
Mr Carson and Mrs Hughes, who according to Word of God have no romantic interest in each other but who are shipped voraciously by a significant segment of the fandom anyway. Jim Carter (Carson) has made no secret that he is a Shipper on Deck while Phyllis Logan (Hughes) is more undecided.
Isobel Crawley/Dr Clarkson was this for quite a long time. Upgrading it to canonical was set into motion during the 2012 Christmas special.
There is a large portion of the fandom who ships Mr. Mosley and Ms. Baxter after the events of season 4.
Fridge Brilliance: The TWoP thread for Downton mentioned how Robert and Cora lack parenting skills. This makes sense when you consider that the people that raised them wouldn't have been their parents, but rather a Nanny.
Fridge Logic: How exactly did the prosecutors know specifically which servants had been eavesdropping on Mr. Bates?
The prosecutor mentioned Mr. Bates gave reports to police. It's unlikely he'd have been anything other than honest and thorough. He likely mentioned that Mrs. Hughes and Miss O'Brien knew things about the situation.
Handing them that information, though, does seem to have put Bates into Too Dumb to Live territory-almost literally.
Referring to the quote on the main page ("we all have different parts,etc."): What a load of crock. If you don't have a need for someone, stop paying them and fire them. But later, when the Crawley family goes through yet more financial difficulty, it becomes clear that this "everyone is entitled to a job" mentality may have been causing this unstoppable decline.
Except that Robert firmly believes it's the duty of a lord to make sure his people are taken care of, i.e. employed. That's almost exactly what he says to Matthew regarding Molesly: yes, Matthew might find him superfluous, but getting rid of him would deprive Molesly of his livelihood.
Though not a dark beauty like her sisters, Edith really is rather lovely in her own way. The way the family talks, though, you'd think her face would send would-be suitors running for the hills. The actress was deliberately cast to still be attractive, but in a different, less-obvious sort of way compared to Mary and Sybil — it drives her character arc. It's likely down to her aquiline nose (rather nice if you like that sort of thing), her very beady eyes and rather narrow face — as well as the fact that her shrewish personality makes her seem less attractive.
The pretty cute Lavinia, who wouldn't need to be such a meek doormat.
Rob James-Collier and Allen Leech's very close friendship in interviews - even reaching Bromance levels at times - has made Thomas/(Tom) Branson a popular couple among some fans.
Matthew and Tom's close friendship in Series 3 also shows signs of this.
Informed Wrongness: Matthew being obliged to keep Molesley and pretend he needs him out of mere charity, though it wasn't even him who has hired a valet.
And Cora's rude way of dismissing Isobel. She could have sent a message of 'thank you for your help, but we will manage from now on', instead of letting her come to work and take the hint from being ignored.
The similarity between the deaths of Sybil and Matthew, giving the impression that if Edith ever has a baby, she and the father will have a 50/50 chance of surviving the next 24 hours. Some fans also wondered why Fellowes didn't have Sybil survive her daughter's birth, so they could both die in the accident.
Followed by Edith having a baby whose father may or may not be dead. Fellowes does know it's possible to do a birth storyline where both parents survive, right?
Sybil and Branson's storyline in series 2 gets there at times, as you start wondering if they have a set time each year to pick up their ongoing conversation where they left off.
The possibility of having to move into a smaller but still extremely nice-looking house in early series 3, which everyone Wangsts about like it's an inner city rathole.
Bates' prison storyline, due to being quite hard to follow without subtitles. This is the peril of setting a story in a place where people have to mumble all the time.
Mary's breakdown upon seeing Matthew's gramophone. Where exactly did she think the music was coming from?
Plus, the oddity of Gary Carr's casting; he's an English actor playing American and his accent is pretty bad — oh, and he can't sing, despite him being cast as a jazz singer.
The moment in Series 2 when Matthew turns up out of the blue at the concert for the convalescents, and starts singing in a slightly camp manner as he walks over to greet Mary is ball-shrinkingly cringeworthy.
In fact, quite a few of Matthew's mannerisms are narmy — the weird, wobbly head motion he does as he nuzzles up to Mary for a kiss is another good example.
Edith learning to drive and looking after convalescing soldiers in series two leads her to become kinder and less concerned with marriage and one-upping Mary. After the end of the war hits the Reset Button on her character, her sudden interest in women's suffrage in the wake of Sir Anthony abandoning her at the altar could be seen as another attempt at this.
Thomas in series 3 as he transitioned from straight-up Jerk Ass to Jerkass Woobie. His falling-out with O'Brien put him on the receiving end of the worst schemes she has to offer, he ends up being outed and almost sacked (or worse, arrested). The moment when he tells Bates the one thing that will make O'Brien back down is a Crowning Moment Of Awesome. Furthermore, he acts a lot nicer to everyone in the series 3 Christmas Special, hopefully foreshadowing a kinder, gentler Thomas.
Ship-to-Ship Combat: For some reason, fans of Bates/Anna and Thomas/Jimmy do NOT get along, despite the fact that there's no reason why both ships can't peacefully coexist. It's probably because Bates and Thomas are almost antitheses of each other and generally if a person likes one, they do not like the other (or their romantic interests). Then this article came out and fans of each ship attacked the related poll with warlike zeal.
Squick: Bates' ill-advised use of a "limp corrector".
Strangled by the Red String: The Tom/Sybil romance in Season 2. What could have been a heartrending story of them slowly falling in love and struggling with their forbidden feelings, turns into a repetitive Yoyo Plot Point. Tom gives an out of the blue Love Confession in the first episode and with a 180 from his previously rebellious, but more vulnerable characterization, Tom continually nags Sybil to run away together, while the normally fiery Sybil makes non-committal noises and ums and uhs. This conversation is repeated Once per Episode, taking up valuable screen time for the characters. The whole relationship really needed some build up and Will They or Won't They? before the proposal was thrown in, and its only the classic Uptown Girl conflict and work of the actors that gives it spark.
Tony Gillingham falls head over heels for Mary in just two episodes, while she's been mourning and far from her most engaging.
Strawman Has a Point: Sir Richard Carlisle was a brute the whole family disliked, but his main actual complaints against Mary were her lingering feelings for Matthew and her slowness in planning their wedding, both of which she denied. Upon breaking their engagement, she became engaged to Matthew that same day and they were married within a few months.
They Changed It, Now It Sucks: Shows up consistently in general fan response to the second season. Some elements of the series are altered drastically with the advent of World War One, although a great deal remains the same, which, in turn, has spawned an outcry from other portions of the fandom, who protest that the narrative glosses over or speeds by too many major global events to be considered realistic. An unfortunate but unavoidable side-effect of setting a drama series during a time of extreme social and political upheaval.
Series 4 had to deal with the loss of three major cast members within the previous year, leading to some awkward writing at times.
Wangst: An in-universe example in Season 4, with Mary after Matthew's death. While she has the right to mourn, all the family, (well except Robert), agree she should be getting over it and reengaging with life, six months after the event.
And of course, to put it in perspective, Tom was in a much worse situation when he lost his wife, as he was stranded alone at his hostile in-laws house but made an effort for his daughter, whereas Mary had her whole family supporting her and basically ignored George.
Branson, oh god Branson. Come Season 3 he's exiled from Ireland, separated from his family, trapped in the house he tried to escape from, lost his wife, (the woman he spent six years waiting for) and left alone with a new-born baby.
Now he's also lost his brother-in-law/best friend who was the only one who understood him.