Sofia and Amber connecting as real friends and sisters at the end of the pilot movie.
Sofia: You have no idea how happy I was when I found out we were going to be stepsisters!
Amber: Sofia... we're sisters.
A subtle example, but in "Just One of the Princes", there's a bait-and-switch moment where Sofia thinks she's getting a majestic black pegasus to ride, but her horse actually turns out to be a small purple Pegasus with small wings named Minimus. Sofia still reacts with joy, and even when Minimus advises Sofia to switch horses (and more than once at that), Sofia adamantly insists that she can win the race with Minimus. And she's right, she does tie for first place with James.
Baileywick having tea with Sofia after she's grounded for bailing James out of trouble.
The ending of "Cedric's Apprentice": Cedric has the chance to use his invisibility potion to steal Sofia's amulet, but because she helped him prove what a good sorcerer he is, he decides against it.
Not to mention the episode's epilogue. Heck, almost all of Cedric and Sofia's interactions in that episode could count.
When Sofia first turns herself into a lizard by accident, Cedric doesn't even think for a second of using the opportunity to steal the Amulet from her, instead reassuring her that she'll be fine before casting the spell to return her to normal. Knowing that he could do it is exactly why she pulled off her Batman Gambit later.
Sofia and Clover reconciling in "Blue Ribbon Bunny."
In "The Princess Test", Amber encouraging Hildegarde to keep going in the test after Hildegard had given up.
And Sofia passing the secret "kindness" test by agreeing to help Mrs. Higgins, and then insisting on continuing to help her even after running into obstacles (even after Mrs. Higgins tries to reassure Sofia into going back for the princess test).
In "Baileywick's Day Off", four simple words at the end after everything that happened: "Baileywick is more important."
Amber and Sofia ending up having a good time together in "Two To Tangu."
The ending of "A Little Witch". Predictable, yes, but heartwarming? Definitely.
In "Princess Butterfly", Amber is about to pull a Karma Houdini: after an episode of trying to take Sofia's amulet, Sofia finally just offers the amulet so Amber can fix her magical butterfly costume without having to admit to the fairies she cheated to win the earlier costume contest. After all, to Sofia, Amber is more important than her promise to her father never to take off the amulet. That's heartwarming enough, but then Amber turns Sofia down of her own accord, having a change of heart at the last minute. After all, it was Amber who lied and cheated to win, so it wouldn't be fair to make Sofia give up something.
The end of the two-parter "The Floating Palace" when both humans and mermaids are getting along well.
Sofia: I'm glad everyone's getting along.
Oona: Me too! It means we can be friends.
Sofia: It means we can all be friends now.
The end of "Holiday In Enchancia", with Sofia, Amber, and James giving their Wassailia presents to the peasant family who has given them shelter from a blizzard. Also when Sofia and Amber hug each other during the ending song.
After defeating Miss Nettle in "The Enchanted Feast," Sofia and Cedric share a brief but sweet hug.
Despite being a source of discomfort for Sofia, seeing Amber and James so eager to spend Mother's Day with Miranda in "Mom's the Word" is very sweet.
In "The Silent Knight," Aunt Tilly shows that she doesn't have problem with Sir Bartleby's voice, telling him she likes "one-of-a-kind things."
Cedric finally proving himself a capable sorcerer, thereby earning his perfectionist father's respect, in "Mystic Meadows."
Sofia and Hildegarde's friendship in "The Princess Stays in the Painting".
A very minor case, but in Hildegard's sad flashback, we see her big sister, who not only invited little Hildy to play with her, but showed concern when she fell down instead of laughing at her like everyone else. It's nice to think that someone as self-conscious as Hildegard might have a Cool Big Sis in her life.
Similar to "Baileywick's Day Off," we see that Sofia and the Royals fully consider Baileywick a member of the family in "Baileywhoops." To elaborate, when Baileywick keeps messing up (no one knows it was the cursed pin yet), no one scolds him or even gets mad at him, only suggesting he should take a break. Sofia does everything she can to help him do better, even promising to do his chores just so he can stay. That's dedication.
Also in that episode, Cedric makes peace with a former class rival, Greylock, and the two work together to save the assembled royals. And Greylock makes sure that Cedric gets his due credit for it, earning a round of appreciation from Roland, something Cedric clearly appreciates.
Everything concerning Sofia and Amber in "The Curse of Princess Ivy", especially Amber Taking the Bullet for Sofia.
Throughout "Winter's Gift," Sofia tries to find a special gift for Cedric. In the end, Sofia gives him a homemade wand case, and he's absolutely delighted.
So much so, that he uses a spell to summon snow for Wassalia, essentially the same type of spell he complained about as a "parlor trick" in the pilot movie, but here he does it gladly and without complaint.
Cedric coming to teach Sofia's magic class in "Substitute Cedric." Naturally, the sorcerer only agreed to it because he needed an herb from Royal Prep's greenhouse, but by the end of the episode, Cedric has had so much fun with the kids that he continues the lesson.
From the same episode, we see Cedric as a child, and he is adorable!
In "Gone with the Wand", when Cedric learns that Sofia has been granted an invite to meet Merlin, his idol, he doesn't even express jealousy, telling her with great enthusiasm that she's been granted quite the honor. The scene only gets all the more touching when Sofia says that the invite allows her to take two guests, and since she knows how much Cedric idolizes Merlin, he was the first person she thought of.
Also, Cedric's niece Calista, who is even more adoring and respectful of Cedric than Sofia, to the point where she even styles her hair to be the same style as her "Uncle Ceddy's". Between her presence and him winning the respect of his lifelong hero, this was a great episode for the show's resident No Respect Guy.
Calista instantly claims that her uncle's friends are her friends, too, as she affectionately hugs Sofia.
"Dads and Daughters Day" has Sofia doubting if King Roland is her real dad, since he is her stepfather. During a school field trip with Roland and Amber, Sofia ends up feeling increasingly like a third wheel. Luckily Roland and Amber are both adamant that Sofia is Roland's real daughter even if he wasn't there from her birth and at no point is she considered just a stepdaughter.
Sofia discovering Roland's pocket watch has two pictures in it: One of Amber and James, which she saw first, and another of her.
When Hildegard points out that Roland isn't Sofia's "real father", Amber quickly calls her friend out, while at the same time, putting a comforting arm around Sofia. No doubts that she was sincere when she dropped the "step" in "stepsister". And for all her faults, Hildegard also immediately recognizes what she did was wrong and agrees with Amber, telling Sofia to just forget that she said anything.
"Camp Wilderwood" has James and Wendell legitimately getting along. This is especially big for Wendell, who is somewhat sociopathic and his Lack of Empathy has prevented him from making friends, which naturally made him lonely and only further fueled his wrongdoing. Finding someone he actually clicks with is something he is clearly joyful about.
"Elena And The Secret Of Avalor" has many including, but not limited to:
Elena being reunited with Isabel and their grandparents
Elena hugging Sofia after being freed
Sofia encouraging Elena by saying that she's not alone
The Royal Family and everyone in Avalor helping Elena overthrow Shuriki
Sofia finally revealing the secret about her amulet, and the family being cool with it.
"Lord of the Rink" has Prince Hugo's father, King Garrick, doing everything he can to spend more time with his son,including becoming the assistant ice hockey coach. After seeing Sofia and Hugo perform in an ice-dancing recital, Garrick goes up to the pair, expected to reprimand Hugo for disobeying him only to exclaim that his son has done a wonderful job. Despite having said that ice-dancing was for girls, Garrick admits that he's proud of Hugo and hugs him right in front of an audience and Hugo not only sincerely enjoys it but isn't even embarrassed nor does he remind his father that people are watching. To top it off, Garrick even makes his decision to be the assistant ice-dancing coach.
In the same episode, when Sofia slides into the hockey net, nobody laughs at her; instead they're all shocked and worried that she'd have hurt herself. Everyone is worried about Sofia, but nonetheless, Hugo was the only one to race to her rescue. The scene is more touching when the whole hockey team surrounds Sofia to see if she's okay.
Hugo's dedication in helping Sofia is very sweet, and it's no less touching that he won't let her give up when she fails to pull off an ice-dancing move. Later, just before the ice-dancing recital, Sofia realizes what a great friend Hugo has been to her, and she decides to be just as good a friend to him.
When the rest of the hockey team catches Hugo ice-dancing, Derek is about to make fun of Hugo only for James and Sofia to stand up for him, pointing out how Sofia went through this experience herself. The other boys decide they're okay with Hugo ice-dancing. After the ice-dancing recital, Hugo's friends ask him to teach them how to ice-dance too.
"Day Of The Sorcerers" has a few stand out moments:
Sofia seeing the good in Cedric even when he betrays her.
Cedric can't bring himself to hurt Sofia even after taking over the kingdom. His Heel–Face Turn at the end makes this sweeter.
The royal family finally showing respect to Cedric is very touching.
"The Mystic Isles" has a few noteworthy moments:
Amber's song, "That's Not Who I Am", starts as a tearjerker about her thinking she's not a real hero, with Sofia reassuring her otherwise, brightening her mood. It really shows the depths of their bond.
During the climax, Prisma tempts Amber to join her instead of smashing the stone that would undo her magic and get rid of her new amulet. Amber than turns her down with the aforementioned smash. It also counts as a Crowning Moment Of Awesome.
"The Flying Crown" has plenty of heartwarming moments:
Hugo's big brother Axel boasts to him how good it felt to hear the Royal Prep cheer during his days as a star athlete at Royal Prep only for their father to chide him, telling him not to hurt Hugo's feelings, and Axel apologizes to and makes Hugo feel better (or tries to)
After Sofia learns of Hugo's Jerkass Façadethanks to his horse Electra, she has a heart-to-heart talk with him, offering to help him win the Flying Crown for his family, and Hugo doesn't even get angry with Sofia for mentioning that nobody in his family has fulfilled that goal.
Hugo is surprised that the crowd is singing the Royal Prep cheer for him and Sofia despite the cheer only to be sung after winning, and Sofia tells him how important teamwork is. She asks him to race with her, and he smiles at her.
Hugo and Sofia smile at each other just before the race starts, which makes their opponents, Vaughan and Vance disgusted and presumably jealous.
When Sofia says they have to do the slingshot, Hugo finally gives in and agrees to sling Sofia instead of the other way around.
Electra becomes nicer to Minimus and says, "That's the first nice thing I've ever said to you, but it won't be the last."
Axel tells that Hugo takes after him, and Hugo doesn't even show any annoyance, instead sincerely and happily saying that he takes after Sofia, making her blush, and Axel isn't even hurt or jealous when Hugo says this.
"The Tale of the Noble Knight" has Sofia meeting Willawing the dragon and her friends. Willawing finds Sofia adorable to the point where she just picks her up and hugs her and gently tickles her chin, which makes Sofia giggle adorably.
In "Through the Looking Back Glass", Cedric reconciling with his sister once the childhood misunderstanding between them is exposed. He even is able to reverse the magic spell that ruined her hair, and she returns to being kind and encouraging toward him rather than condescending and superior.
Prior to this, after Sofia and Calista learn the incident that broke a bond between Cedric and Cordelia, the girls return to Calista's room to find that Cedric had been watching. Why is this heartwarming? This would imply that Cedric had been looking for Calista and Sofia and went into his niece's room to find them only to see that her Looking Back Glass is showing the incident.
When Sofia and Calista learn why Cedric's magic spell ruined Cordelia's hair, Calista tries to save her young mother from being affected by the tainted serum. Unfortunately, young Cordelia is unable to hear her future daughter, making the rescue unsuccessful.
In "Too Cute To Spook", even after she repeatedly messes up, Sofia keeps defending Callista each time.
Small moment, but Sofia reuniting with Kai in "The Mystic Isles: The Falcon's Eye" deserves some mention. Kai happily gives Sofia a Bear Hug and picks her up and kisses her on both cheeks.
Usually, it's Sofia who tells Amber that they have to save a friend or loved one, but in "Her Royal Spyness", when Amber and Sofia think their mother is being taken by a sealian, it's Amber who tells Sofia that they have to go after her themselves, and without a second thought at that.
The ending to "The Mystic Isles: A Mystic Wassailia" is full of this. After helping everyone out and making sure they have a great Wassailia, it's then discovered that the reason Chrysta keeps asking to do the protector duties is because she doesn't have any family to celebrate with, hence why she does a little activity at each destination to make herself happy. The moment goes from tearjerker to heartwarmer when everyone gathers to celebrate the holiday with her, saying that she's like family to them.
In "Best in Air Show", Grand Mum comes to see her family. She straightens Roland's crown and hugs her three grandchildren. As for her and Miranda, normally, the in-laws get to know their children's spouse before deciding whether or not they like them, but Grand Mum quickly warms up to her daughter-in-law and kisses her on both cheeks.