On the B&W series, I believe it to be either
Astroboy goes to school, or
A Wonderful Christmas. The former because Atom somehow ends up under the duncecap, and several other cute gags, not to mention the refueling gag. While the latter, because the way the robotic house rocks the kid and all his animal friends to sleep, the wind up key on the bad guys' tank, and the suction cups they shoot at Atom, and Uran on skis. Note that I have only seen the 36 that are available through
The Right Stuf, so my comments pertain to those alone.
Without a doubt, the color remake's funniest has to be
The Robot Vikings. There are dozens of sight-gags in just the first few minutes, even Osama takes part in one. It happens so quickly, that I had to rewind the tape and view in slow motion just to be sure, but there he was. The gags that occured while Atom was dressed in his puppy-dog costume were also very amusing, and those were all I remembered until viewing it again yesterday. That one must be the funniest!
![Laughing :lol:](./images/smilies/icon_lol.gif)