Astro's stunned reaction to the first time his rocket boots fire, including a hilarious expression and a wonderfully prompt (and pretty harsh) slap to his own face.
And then as shock becomes delight he tries to zip off heroically - only to briefly forget how to power the jets and, on reactivating them, slam himself backwards into a building and then straight up through its stone facade.
A soldier trying to use windshield wipers when Astro crashes into his ship. Astro's look of sheer annoyance is priceless.
Trash Can the robot dog's final attempt to "out" Toby as a robot, spelling out on the ground in huge letters "HE'S A ROBOT!" with an arrow pointing to Astro/Toby to Zane. Made funnier when Zane shrugs, "Almost makes me wish I could read!"
When the RRF 'rescue' Astro.
Zane: What just happened?
"I'm voting for the other guy!"
When Astro descovers his "accessories".
Astro: What? I got machine guns... in my butt?!
When Astro saves one of the guy's after him, and then has to deal with the reinforcements.
Astro: What is up with you guys?
Guard: I love you man.
Any scene involving the Robot Revelutionary Front.
From the first episode, the Inspector asks Dr. O'Shay about the blackout caused by reviving Astro. His explanation? "I can't sleep with the lights on."
Anytime someone bangs down Tenma's door. Made better by his sheer calmness about it.
Tenma: (surrounded by police) So many visitors. And I didn't even make tea.
