Kimono promising to treasure her charm bracelet and the ponies' friendship forever.
Skywishes' encounter with Star Catcher in Dancing in the Clouds. Secretly, Star Catcher been with her for years, even though she felt she could never show herself so as not to reveal the secret of the pegasus ponies' existence. Finally, she does, taking her flying and showing her Butterfly Island, but only her.
Skywishes meeting Baby Honolu-Loo in "Friends Are Never Far Away."
The ponies dropping everything to rescue Minty in A Very Minty Christmas.
When they rescue her and Thistle Whistle, the ponies hug, and the power of their love makes them and the Celebration Castle glow.
In The Princess Promenade, the Breezies give Wysteria a cloth and shower cap to simulate being a princess, and she decides it could be fun.
Wysteria finding the ponies made a float just for her.
Wysteria didn't want to be a princess, especially after finding out how far it would set her apart from the other ponies, but finding out that if she rejected the role, it would return Spike, whom they'd all just met, to hibernation quickly puts an end to the idea of saying no. She figures out how to Take a Third Option in the end, but she it seems would have chosen to live a life she didn't want if it had proven to be necessary for Spike to live at all.
There's the way that everyone comes together to support their new princess, and taking over her workload so she could train for it, and generally making Wysteria herself the only one who had a problem with her having the role.
Finally, there's the reunion of the Breezie trio.
In The Runaway Rainbow, Minty, Pinkie Pie, and Rarity are trapped in a river that's headed for a waterfall. Rainbow Dash and Spike, who were proud of appearances, immediately wanted to jump in and save the ponies and even argued over who would. Not to mention the fact that they would be risking their lives.
Rarity reuniting with the other unicorns in The Runaway Rainbow, as well as the song "So Far Apart."
Star Flight and Heart Bright's closeness in "Two For The Sky." It invites the usual speculation, but it's just all very cute, the way they can answer each other in rhyme and get the same Zany Scheme ideas at the same time, and even have the same dreams.
Lily Lightly's song with the firefly, where she learns being different helps her shine.
Lily Lightly coming back to Unicornia to find everyone else attached lights to their horns because they were worried she felt ostracized.
G3.5 has "That's What Makes a Friend," as the ponies tell Whimsey Weatherbe the qualities good friends have—finding you get along well, common interests, embracing differences, sharing feelings, and learning to count on each other.