Courtney giving up her plan of taking out the other winners and runner-ups in the second challenge. She realized she made a mistake when she chose money over friendship. Too bad she blew it at least six episodes later...
The gang cheering up Bridgette after Geoff got eliminated. It turned out to be EZEKIEL, of all people, who ends up cheering Bridgette up in the end.
Gwen decides to keep Heather's secrets, even though she did have the temptation to humiliate her.
Twilight willingly giving up Mrs. Buzzy to Heather to blow it up rather than Heather's stuffed cat mainly because Twilight knew she'll sew up Mrs. Buzzy later on.
The moment Nyx comforts Courtney and Duncan in Episode Eight.
The alliance between Lindsay, Sierra, Katie, Sadie, Izzy, Dawn, and Bridgette. They even started calling themselves the Main Seven, with Lindsay giving them their own Elements of Harmony jewelry.
For those wondering which element each of them have, Lindsay is Magic since she kept the crown she made for herself in the first challenge (Izzy won the challenge for her team, her version of the Elements were used in the first challenge), Sierra is Honesty, Katie and Sadie are sharing Generosity, Izzy is of course Laughter, Dawn is Kindness, and Bridgette is Loyalty.
Heck, they even do their own version of "A True, True Friend".
Sadie convincing Katie to stay in the game for both of them whilst Sadie goes off with the others on a mission to search for the eye. Sierra also contemplating quitting the game to give protection to everyone also qualifies as well.
Despite all the crap that Celestia, Luna and Discord put Chris through in the ending Chapter 16, they were actually glad that he was back to normal.
Another sweet moment between Celestia and Chris is when they are dancing with each other underwater in Chapter 19, as friends.