In the direct-to-video Pilot MovieBuzz Lightyear of Star Command: The Adventure Begins, Buzz (voiced by Tim Allen) jumped into the Unimind, purified it from Zurg's evil influence, as it spreads across the galaxy to remove Zurg's mind control, shouting "To infinity... AND BEYOND!..."
The four-way "Mirandizing" of Zurg a few scenes previous runs a very close second.
Mira: Evil Emperor Zurg, by the authority of Star Command.
Booster: Section 5, sub-section zeta! That's the one about the "evil emperor".
XR: You are under arrest.
Buzz: Like I said, evil never wins.
The movie's introduction to Mira Nova, who bests the Level Ten training robots by ghosting out of her suit to make them believe they've beaten her. She then ghosts through two of them and tears them apart, and takes control of the last one to smash the rest.
In the pilot movie, when Mira helps Buzz phase inside the Uni-Mind's core to try and save the galaxy from Zurg's mental influence. When Buzz gets sucked in all hope seems lost... then we hear Buzz's catch phrase come out of nowhere.
Buzz: To infinity...AND BEYOND!!! (a wave of Uni-Mind energy spreads out and blankets the entire galaxy)
Any time Zurg drops his hamminess and engages in full on evil mode. It's especially spine tingling when he starts off a sentence in his typical comedic fashion and then drops his tone into something cold, dark and threatening.
Zurg: I'm not going to kill you. Nooo. No, I have a much more delicious idea. I'm going to take the galaxy's greatest hero and turn him. Into. Me.
The 'real' Shiv Katall (Commander Nebula) in the episode of the same name.
Ty defending Commander Nebula from XL. He might be discharged and devoid of weapons, but there's no way he's going to let anyone get hurt. It also counts as a Crowning Moment of Heartwarming.
Ty: Get away from my former Commander! (kicks XL in the back)
The eventual fate of NOS-4-A2, thanks to the Wirewolf.
Commander Nebula after being kidnapped by XL. He's chained up, imprisoned in a cage, under a web of laser beams, and at the mercy of a psychotic robot, but he remains defiant until he's rescued.
When Buzz goes up against Gravitina in "Opposites Attract". After suffering a Heroic BSOD through most of the episode, Buzz decides to go up against Gravitina after she swelled his head and endangered his team. And it is GLORIOUS.