It's a beautiful moment when William finally gives Thomas the beatdown he's been asking for all along. Made all the better by the fact that everyone stands around watching in tacit approval until Thomas starts to hit back. Then everyone jumps in to pull them apart.
Anna finally laying down the law and telling Bates that he was going to marry her, now, because she's stood by him come what may for seven years, and she absolutely will not face their coming trials as anything but his wife because she refuses to be pushed to the sidelines with no proper place in his life. Guh.
When a dying William wants the local vicar to wed him and Daisy, the Vicar refuses, because he's of the opinion that Daisy just wants to reap the financial benefits of being a war widow by marrying William. Cue The Lady Grantham inviting him for tea and letting him know PRECISELY why you should never mess with the Dowager Countess.
Robert chewing out the white feather girls in the series 2 premiere.
To elaborate, the white feather girls are rude, stuck-up pricks who hand out white feathers to men not in uniform and quickly inform them that it's for cowards who were too chicken to enter the army. They do this to William during a fundraiser for the war, and Lord Grantham FLIPS OUT ON THEM, interrupting the entire orchestra as he loudly orders them to get lost.
Cora supporting the free kitchen for convalescing soldiers that some of the servants have set up, and forcing O'Brien to work in it.
Matthew laying the smackdown on a very smug Sir Richard, after Mary breaks their engagement and Sir Richard insults both her andLavinia. This is followed by Sir Richard trying to scrape together his dignity to tell the Countess Dowager that he's leaving and will most likely never meet her again. She shoots him down with "Do you promise?"
Martha Levinson showing some extraordinary quick-thinking and improvising skills when she reorganizes the Crawley's entire fancy dinner for dozens of guests after the ovens stop working and there is no dinner cooked. For all her early cattiness and impertinence, she really saves the day for the Crawleys on more than one occasion.
For 3.08: three words - "Her Ladyship's soap."
When Thomas tells Carson that, while he may not be like other people, he is not foul. The quiet dignity in the line makes it a CMOA whether you're a Thomas fan or not.
Sir Anthony spotting a nasty prank to make Branson appear drunk, and turning everyone in the room against the asshole who did it, including his own father.
All the Crawley women standing up to Robert when he tries to shame them into leaving a meal prepared by Ethel.
O'Brien detecting Wilkins' plan to get her drunk, and telling her that now she isn't bound by any sense of loyalty to her. Do not try to out-O'Brien O'Brien.
Cora's swift firing of Nanny West, after she discovers her being abusive towards baby Sybie, whom she spitefully refers to as "that chauffeur's daughter" and a "wicked crossbreed". Do not talk shit about Sybil's daughter when Cora's around.
Mrs. Hughes seeing through Edna's Baby Trap ploy, and sending her packing out of Downton on nothing more than a guide to contraceptives and threats.
Mrs. Hughestearing into Mr Green telling him exactly what she thinks of him, and to keep a low profile if he values his life. She's in a room alone with this man. And she completely loses her shit when he claims that both he and Anna were to blame.
Carson and Branson repeatedly standing up for Mary in 4.01-02, letting her know that they are on her side.
Daisy giving Ivy the telling-off she's had coming for a while, with Mrs. Hughes backing her up.
Bates singlehandedly saving the royal family from an adultery scandal.
Edith doesn't get many CMOA's, but a subtle, but powerful one occurs when she reminds Isobel, following Matthew's death, that she still has a lot to live for — "You're a grandmother."