Sid standing up to Mama Rex. Sure, it's something of a jerk move because he basically stole her eggs (albeit while thinking they'd been abandoned) and has no real custody claim to the babies, but it's still Sid refusing to back down from a T-Rex.
Ice Age: Continental Drift
Louis standing up to Gutt and rescuing Peaches
Diego roars... the Earth stops shaking.
Manny vs. Gutt. 'Nuff Said.
Manny: Sometimes it pays to weigh eleven tons!
Precious turns out to be not-so-imaginary.
Sid aiming Precious's water jets to take out the pirates one by one, and his granny piloting Precious from inside her body.
The Herd and the hyraxes stealing Gutt's replacement ship.
Ellie squishing Squint into the ground.
Peaches using her tree-swinging to knock Gutt off the ship.
So Manny stole Captain Gutt's ship. What does he do? He BREAKS AN ICEBERG IN HALF to make a new one. Holy shit.
The impressive thing isn't that he MADE the ship, it's the fact that he crawled between a fissure, barely any room for him to fit, and using just his feet strength, broke the ice berg in half.
That Captain Gutt and his crew got to the continent and captured Manny's family well before the herd (who had at least a half hour lead on them) got there without even seeing him pass them. Even with narwhal power, it's still impressive.