Dr O'Shay's secretary Yoko gets one when she disregards his orders to evacuate, and returns to save him from Tenma's robot dog. With a laser gun.
Yoko: Put a muzzle on it, Tenma.
Rainbow Parakeet has planted bombs all over the robot revolutionary Blue Knight's sanctuary and is about to press the button on the detonator, taunting Astro that the only way to stop him is to kill him and prove he's just as ruthless as Blue Knight. Astro opens fire on him and apparently misses. Cue maniacal laughter as the villain presses the button. Click, click, click. Turns out Astro decided to Take a Third Option and was actually firing at the communications antenna that would relay the remote detonator's signal.
Don't forget the episode where a robot train was remotely hijacked and Astro had to get rid of the bomb. That kid can fly pretty damn fast when he needs to.
"Battle Bot" The entire attack on the space station.
"Escape From Volcano Island" When Astro spins with his Arm Cannon and generates a giant shield to protect the boat from the erupting volcano.
After spending almost the entire show as a Karma Houdini, in the second-to-last episode Mr. Drake makes one last attempt to destroy Astro by stealing a Humongous Mecha and then crosses the Moral Event Horizon (for the umpteenth time) by trying to shoot Astro's friends out of the sky. This manages to jog enough of Astro's memory to reactivate his powers and dish out an effortlessCurb-Stomp Battle to Drake in a matter of seconds. Followed by Drake finally being arrested for his crimes.
Astro Boy (2009 film)
After Astro is captured and deactivated, Dr. Tenma suddenly turns on Stone and, with Dr. Elefun's help, snatches the Blue Core so he can reactivate Astro, assure him that despite not being Toby Astro is still Tenma's son, and send Astro off to escape while Tenma and Elefun face the military. The interaction between Astro and Tenma makes this the Crowning Moment of Heartwarming too.
Astro defeats a coliseum full of robots, slows a falling island enough to minimize damage and casualties, and flips a skyscraper-sized baddie that has absorbed most of the air force's weaponry over his head. Astro is Badass Adorable, plain and simple.
Zog, the giant robot Astro revived, is about to crush Hammegg who wronged them underneath his foot. Hammegg protests that he can't, due to the laws of robotics, which have apparently been in use for 50 years. Zog, who was built far earlier than that (100 years), simply says:
The fact that he's voiced by Samuel L. Jackson probably made it far more Bad Ass than it would be if it were anyone else.
The scene where Astro learns to fly and then spends a few minutes playing in the clouds, with the scene culminating in his iconic tunnel-through-the-mountain. Whatever your overall opinion of the movie is, if you didn't find this sequence thrilling something is wrong.