Haku giving Chihiro the pill that stops her disappearing, and then demonstrating that it's worked by them gently touching hands. It's easy to miss, but Haku's expression softens and shows the first implications that he's not as cold as he makes out to be. Helped by the very sweet music.
When Chihiro tells Haku his true name, he turns back into a boy and they perform a Headbutt of Love while flying through the air.
It quickly becomes evident that Lin isn't as grumpy or mean as she originally appears. She seems delighted to hear that Sen got a job, wades through swamp muck yelling that she's coming and she won't let the supposed stink spirit hurt Sen, and even delivers a platonic "If You DoAnythingTo Hurt Her!" speech at No Face.
The ending of the English dub version, where the last lines are Chihiro's cutely matter-of-fact "I think I can handle it." as regards the prospect of transferring to a new school. Even if her parents remembered and learned nothing from the ordeal, she did. This is a girl who just faced down practically the entire spirit world by power of will and virtuous behavior... real life is so going to get its ass kicked, and you know it.
At Zeniba's house, Chihiro is sick with worry for her parents and Haku. Suddenly, the windows rattle and with a smile, Zeniba tells Chihiro that their guest is on time. Chihiro goes and opens the door... to see Haku, in all his perfect, dragon-formed glory. There are no words to describe the joy on Chihiro's face as she runs up to Haku and gives him a tight embrace.
And before that, Chihiro needed to confront No Face and Yubaba, so she told an unconscious Haku to not die and that she'll back soon
Lin: "What's going on?"
Kamaji: "Something you wouldn't recognize. It's called love."
Chihiro and her companions have just gotten off the train, and are standing there, probably wondering what to do next. A lamp with a foot hops squeaking out of the forest and bows to them, then hops away again. They follow it. A moment later, the camera cuts to a farther-back view, and the most beautiful, heartwarming little tune starts playing.
Then there's the hair tie that Zeniba gives her.
"It will protect you. It's made from the threads your friends wove together."
If you watch it with subtitles, you can see how much that they changed from the Japanese script to the adaptation. Like Haku bargaining his life in exchange for allowing Chihiro to return home. That's right: if Chihiro hadn't figured out his real name, Haku would have been killed. That enough love for ya?
Three Kamaji moments:
A small one, but calling Chihiro his granddaughter. Sure, it's a cover story, but his tone of voice, at least in the English dub, sounds so much like a real grandfather introducing his granddaughter to other people.
Even better is that before that moment, he wasn't overly fond of Chihiro, insisting that he had no work for her and getting angry when she throws the piece of coal into the furnace (he accuses her of trying to take work from the enchanted soot). And then he just lies so casually, to keep her from getting into trouble with Lin.
He covers Chihiro with the quilt when she falls asleep in his basement.
Giving Chihiro the train tickets that he's been saving for forty years.
It's still rather creepy, but No Face asking to see Chihiro after he has been poisoned by the greed in the bathhouse. Even though he's gone so bad, he still wants to see her and, in his own twisted mind, repay her (by that point, he is mimicking the bathhouse employees and believes that giving Chihiro gold will make her happy).
The Youkai's transition while Chihiro is at the bath house. They are full of Fantastic Racism towards Chihiro when she first arrives, but after she asserts herself and proves to them that she isn't as useless as they perceived her to be, she seems to grow on them. For example, the Foreman - who had previously denied her bath tokens - doesn't find her struggling to get the stink spirit cleaned amusing after she leads it to the bath, and later he shows genuine concern when she goes to confront No-Face. The frog and human-esque Youkai that she saves by feeding the spirit's medicine to No-Face vouch for her when they are talking to Yubaba about Chihiro's punishment. Other characters, like the boiler man, who were initially jerkish at first eventually come around (though some are faster than others). At the end, all of them cheer for Chihiro when she successfully finishes Yubaba's test.
The River Spirit after Chihiro helps him, the first thing he does is tell her "Well done.". He then gives her the herbal cake, before flying out joyfully laughing. Bonus points, since the spirit didn't know, nor cared that Chihiro is human and is grateful of the help regardless.