What has been dubbed simply "The Road Scene" in episode 2x08. Dr Turner finds ex-Sister Bernadette on the side of the road after she has been released from the sanatorium. Since she's no longer a nun, they are now free to act on their feelings for each other. And they do. Magnificently. Keep in mind, the dialogue below is said during a Held Gaze after he's wrapped her up in his coat and is laden with months, if not years, of unspoken love between them.
Dr Turner: What if it had started raining? What if you'd got lost?
Sister Bernadette: I was lost. I got the wrong bus.
Dr Turner: I was on the right road.
Sister Bernadette: Yes. [deep breath] I know you so little but I couldn't be more certain.
Dr Turner: I am completely certain. And I don't even know your name!
Sister Bernadette: [beaming from ear to ear] Shelagh.
Dr Turner: [tenderly] Patrick.
Sister Bernadette: There. We've made a start.
In episode 2x05, Nora, the older woman who got pregnant after she'd already had eight children, survives falling into a coma and finally gets to move her family into a bigger home. And it's out in the country! It's at first implied that she'd died, but it turns out to be a bait-and-switch and we see her strolling through a field with her family.
Chummy and Peter's relationship, full-stop.
Six words: "Please will you marry my dad?"
In the second season finale, Jimmy tells Jenny about his baby daughter, and how even though it's more exhausting than he expected to care for her, he loves her very much. There's also his obvious desire to see that Jenny is happy and not pining away for him, even though he already confessed his love to her earlier.
When Winnie gives birth, it's immediately obvious that her husband Ted is not the father of her son. The midwives, Dr Turner and Winnie herself are naturally expecting (and dreading) that Ted will be furious, but to their astonishment and joy Ted immediately accepts the baby and proves to be a loving and devoted parent.
The Reverend Appleby-Thornton's explanation for his constant chatter, which is also something of a Tear Jerker:
It was in the silences at the dinner table that I felt my parents' hatred for each other. So I became accustomed to filling them. [...} I talk so I won't know what the silence holds.
The relationship between Sister Bernadette and Sister Julienne is absolutely full of them.
When young Timmy Turner is struck down with polio, Shelagh is not allowed to stay with him at the hospital because she hasn't yet married his father and she's not his biological mother. Also, she's been avoiding all of Nonnatus because she's afraid of what they'll think of her for leaving the Order, but in that moment of crisis she goes back to the place that has always been her sanctuary, joining the nuns' plainsong during their evening service and quietly slipping her hand into Sister Julienne's as she joins them in song. Later, as Julienne is tenderly tucking her into her makeshift cot:
Julienne: Did you believe for one moment that we wouldn't want you here tonight? That we wouldn't welcome you with open arms?
Shelagh: I turned my back on you, Sister. I walked away. I became someone else.
Julienne: No, you didn't, Shelagh. You found joy — and I've never questioned it.
Shelagh: [brokenly] But there's no joy now.
Julienne: But there is love — and it's Christmas. Have courage.
[Julienne holds Shelagh as she cries]
Julienne's words when she asks Julienne to give her away at her wedding:
Shelagh: You should be giving me away. You should be walking with me.
Julienne: [visibly struggling not to cry] You belong to no one but yourself — and you know exactly where you're going.
When Shelagh walks down the aisle to marry Dr Turner, Julienne is sitting in the front row of the left side of the church, in the seat closest to the centre aisle — the place traditionally reserved for the mother of the bride.
After obtaining a hearing aid for Crazy Cat Lady Mrs. Jenkins in the first Christmas special, Dr Turner whispers "Merry Christmas" in her ear. The look of utter wonder on her face, when she probably has been going deaf for several years, is wonderful.
The end of episode 2x2, when Peter gathers all the Cub Scouts, midwives, and Sisters to serenade Chummy with their song "You Are My Special Angel" before they leave for Sierra Leone, where Chummy spends six months as a missionary.
Douglas Roberts, in season 2, deciding that he was going to keep his son, born with spina bifida and convincing his wife to agree with him by making her realize how much she loves the baby.
Also, her picking up her son after refusing to do so the whole episode.
Ruby Douglas: He's not an it, he's a baby. He's my baby boy.