Very small one in the Season 3 finale - as Don and Peggy walk into the office, it cuts to a reaction shot from Harry and Pete - Pete is a little disconcerted, but Harry looks adorably delighted that Peggy is coming aboard.
Don showing up at Peggy's bedside after she has the baby. The advice he gives her might not be great, but he thinks it is (and it does work out for her to a certain extent), and it's touching that he was concerned for her and that he recognizes that she's in a similar position to his even without knowing the details of what happened.
Your mother told me you were quarantined. TB. I expect that was supposed to lessen my concern.
It's almost too little, too late, but Don and Joan talking at the hospital, after the lawnmower incident. You realize that Don may be one of the only people in the world who gives her every bit of respect she deserves and acknowledges that she really runs/ran, at that point Sterling Cooper.
Also, earlier at the party, Peggy taking her aside to say that she hopes Joan realizes she didn't just ignore all her advice — "It's just that we can't all be you" — and Joan replying that she does consider herself to have had a hand in Peggy's success.
Speaking of Joan, her appearance at the office in the Season 3 finale. She's the only damn person in the entire building to actually know how the whole company works and everyone, including Roger, Don and Bert Cooper acknowledges that.
Don carrying a sleeping Anna to bed right after he finds out she has cancer and painting her living room without being asked in 4.03.
Dick + Anna '64
Paul and Joan reminiscing about their failed relationship and then dancing together at the very end of the Election Night party in 1960. One, two, cha-cha-cha.
Don and Peggy in "The Suitcase", once Don stops acting like such an asshole. They steal each other's dinner at a diner, get drunk, and end up curled up on his office couch. In the morning, Peggy is there when Don calls California, discovering that Anna died. He breaks down, and Peggy puts an arm around him:
Don: She was the only person who really knew me. Peggy: That's not true.
The end scene the day after when Don calls her in. Peggy and Don are looking over something that Don had finally come up with and they discuss it for a few. During a pause, Don reaches over for Peggy's hand, squeezes it, and lingers there as they look at each other smiling. Anna may be gone, but he recognizes a kindred spirit in Peggy.
And, of course, it's an echo of the end of the first episode. How far we've come.
Bert Cooper's eulogy for Ms. Ida Blankenship: "She was born in 1898 in a barn. She died on the 37th floor of a skyscraper. She's an astronaut."
After Don has a panic attack because he thinks the feds are going to discover his secret during an otherwise-routine background check, Faye stays with him despite him asking her to leave, and when he, tired of running, tells her about his identity theft, she stays with him. This is in stark contrast to Betty's (pretty much justified) reaction the previous season. Close to the end of the episode, she tells him that they'll do whatever it takes to keep him safe. This is particularly heartwarming, considering he thought that, with Anna gone, there was no one else in the world who could know him and love him anyway.
Betty genuinely being happy for Sally when Don gets her tickets to see the Beatles at their Shea Stadium concert.
Sally's delight at finding out she's going to see the Beatles.
Don anonymously making Pete's contractual payment to the company coffer, repaying Pete for taking the fall for losing the government contract that would have exposed Don's identity.
Also, the fact that Pete immediately starts trying to help Don cover himself after he realizes that the security clearance is threatening him. How far they've come since the Season 1 blackmail attempt.
Much of The Beautiful Girls with Sally and Don's interactions, Sally trying to show how much she wants to live with Don and Don trying to be a good father. The Rum French toast was awesome. A very subtle one is Don telling Sally they can only go to one place, and have to be at the office at noon. In the next scene, they arrive at the office just before 5 o'clock.
The scene between Don and Bobby in "Three Sundays."
Bobby: We gotta get you a new daddy.
When Don and Betty drive home after their dinner with Bobbie and Jimmy Barrett as "Lollipops and Roses" plays in the background.
Betty: I'm just so happy. When I said I wanted to be a part of your life? This is what I meant. We make a great team.
YMMV on this - considering Don actually accomplished their goal for the night by sexing up Bobbie in the coat room (without Betty's knowledge), this troper actually found himself feeling pretty bad for Betty for a change.
Lane and Joan's chat in his office, where he goes as far as to recreate Megan's cabaret routine to cheer her up.
Don being a proud and concerned dad to Sally in "At the Codfish Ball": "You know what makes me happy? A beautiful young lady who will someday be wearing makeup, but not today".
Harry giving Paul $500note The equivalent of ~$3,500 in 2012. so he can start a life outside the Krishnas. As Paul says, while the Krishnas keep saying that they want to help him, Harry is the first person who actually has.
Betty hugging Sally, who is distraught over having had her first period.
The bittersweet ending scene of "Commissions and Fees" where Don lets Glenn drive his car after asking him "What's the one thing you want to do most in life?" Glenn had asked Don why everything turned to crap and in an effort to cheer him up, he let him do that. It was just a really bittersweet end to the episode.
After a rather awkward parting in "The Other Woman", Don and Peggy meet again in "The Phantom" where they finally treat one another as equals. It shows how far both of them have come.
Finding out in the season 6 premiere that even though she's been at a rival ad agency for months Peggy and Stan call each other late at night to laugh about work. Their relationship has come along way and they've developed a great friendship.
Don taking his son Bobby to see Planet of the Apes even though Betty is punishing him by forbidding him to watch TV.
Bobby trying to comfort the black usher after Martin Luther King's assassination by telling him that people like to see movies when they're sad.
Don and Betty visiting their son Bobby at summer camp on "Parents Day" and singing "Father Abraham" with him in the cafeteria.
Betty offering Sally a cigarette. That's right, the characters in this show are so dysfunctional that a mother offering her teenaged daughter tobacco is heartwarming.
YMMV, but seeing Peggy so happy while interacting with Ted was pretty adorable....at first.
Glen demonstrating his loyalty to Sally and kicking his friend Rolo's ass after the latter tried to coerce her into making out with him and called her a tease.
Ginsburg has an anxiety attack before the Manischewitz meeting and Bob tries to calm him down. Stan gets offended. "Oh him you can talk to him? Ginsberg: "I love you, you know that, you're a mother hen." and Stan accepts it. This after telling Peggy he hated Stan a few episodes earlier!
The look between Sally and Don as Don takes the kids to the dilapidated whorehouse that he grew up in that seems to show an understanding between them.
Followed by Judy Collins' cover of the Joni Mitchell song "Both Sides Now" playing over the end credits.
Joan inviting Roger over Thanksgiving (even if Bob Benson was also there) and his feeding their baby Kevin.