Just as it looks like Littlefoot and Cera are about to be devoured by the Sharptooth's toothy maw, cue Mama Longneck's massive tail, which smashes the predator off its feet and into a mound of rock — she then proceeds to take on the Sharptooth single-handedly.
The Lone Dinosaur from #6: a celebration of badass longnecks.
Also from 6, The 2v2 battle at the very end.
In a scene that's a Crowning Moment of Awesome, Crowning Moment of Heartwarming, and a Crowning Idiot Hero Moment all at the same time, Littlefoot ends up jumping off of a cliff into a shark infested ocean to save Chomper from drowning.
Not to mention the fight between Chomper's parents and the enemy sharptooth.