The climax of "The Return of Tambelon". After over 30 minutes of screentime spent suffering defeat after defeat against Grogar, all the good guys have finally been captured in his dungeons. Cue them combining their various abilities for an escape plan worthy of MacGyver, turning Grogar's own army against him, and finally destroying his power to the triumphant tune of "Let the Bell of Freedom Ring".
"The Magic Coins" has the ponies' adventures to get three treasures for Niblic the troll; when he rejects them, Megan offers him something even better, from one of his own coins—a friend.
"The Glass Princess" has Shady come up with the plan to save the day.
In "The End of Flutter Valley," the Little Ponies and Megan save the Flutter Ponies from Queen Bumble and the bees, and together they defeat the Witches of the Volcano of Gloom.
The fact that the bees manage to capture and subdue the Flutter Ponies is pretty awesome.
Sting cements his HeelFace Turn and calls out Queen Bumble for her selfishness. This is followed by him punching out Pointer, twice.
The best part? The second fight involves them actually fighting one another, ending with Sting punching Pointer out of the sky. It's pretty obvious WHY Sting was The Dragon.
Honeysuckle nabbing Bumble with her own crane machine and threatening to drop her into a deep pit if she doesn't let the Flutter Ponies go.
Granted, it doesn't work, but Megan's attempt to free the Flutter Ponies? March up to Bumble and demand she let them go and bluffing that she's surrounded while the others move sticks to give the illusion of it. While being held at stinger point by her entire army without batting an eye. Megan is a badass no questions about it!
The Stonebacks arriving just in time to save Megan and the Flutter Ponies, commanded by Honeysuckle.
Also one for Megan, given she thought ahead and summoned them. When she realizes that they've arrived, she gives a Badass Boast and more or less tells Erabus he's screwed to his face.
The Crabnasties defeating the Flories and saving Posey's garden. The leader is even voiced by Optimus Prime.
"Quest of the Princess Ponies":
Lavan deserves some credit: he succeeds in stealing the wands within moments of introduction, figures out how to steal their powers on his own, and is likely the second most implacable villain in the series after Grogar.
Megan blinding the god-like Lavan and saving everyone by dropping a tapestry on his head.
The Final Battle with Lavan: Lavan is so immensely powerful even Megan admits he has them dead to rights if they can't get to the Heart of Ponyland quickly, blowing the room apart trying to kill them. A combination of Sludge, the Ice Orcs, and even the Bushwoolies keeps Lavan busy, buying the Princess Ponies enough time to recharge their wands at the Heart and finally destroy Lavan by sending his own attack back at him.