Orange Sherbet's act of Generosity. The power in the museum is blown, locking down a security door keeping the group from reaching the Elements. There are no fuses left to replace the blown one. What does she do? She removes and takes her hairpin (the first gift she got from her husband) and shoves it in.
The full story of how she got that hairpin in the first place is so touching it moves Twilight to tears. Thankfully, it's restored after they defeat Nightmare Moon.
For that matter, Blossomforth's act of Loyalty. Separated from the rest of the Manehattan 6, she comes across a family of ponies who were unable to escape the Equestrian Museum of Supernatural History when Nightmare Moon made her arrival and helps them to escape. Upon being offered to escape with them, Blossomforth refuses, saying that her friends still need her. Considering how much of a Shrinking Violet she is, this speaks volumes as to Blossomforth's courage.
This has since been revised and replaced with Octavia's act of Kindness. Seperated from the others, she uses music to calm the distraught family and leads them to safety. Blossomforth, meanwhile, gets an Awesomely Heartwarming moment by putting her life on the line when Twilight declares We Need a Distraction, despite her fear, because she trusts Twilight.
A small one, but Orange Sherbet getting Spike funnel-cake, knowing he'd not like the food at lunch.
The story of how Orange Sherbet and Mosley Orange hooked up.
Tangerine's interactions with Babs and Applebloom.
Orange Sherbet patching things up with her family, especially Applejack.