See, it is obvious to many of us that whoever wrote the cartoon He-man was either not a male or else had never been married. Why else would he have said, "I have THE POWER!"
Any married male knows far better than that. But that is far from the best tag line from a cartoon. For example, think about G.I. Joe. "A real American Hero" was the tag line. Lets think about that for a few ticks.
How, exactly, can a plastic and metal toy be a "real" hero, American or otherwise? Then you remember...we are America, we can do whatever we want. If we want to make a fictional plastic character our real hero, we can do it if we want.
It could be worse. It could be Voltron..."and "I'll form...the HEAD". What, is it some poor sap with a size 9 head? How do you form a head? Do I really want to pursue this line of questioning to its inevitable and nasty conclusion?
The Transformers of course were a veritable plethora of idiotic catch phrases: "More than meets the Eye" but less, apparently, than meets the belly. "Autobots...transform and roll out!" Why these super-advanced beings would choose a horseless carriage as their means of transportation is a bit beyond me, but...whatever.
By the power of Greyskull, I think we have a winner. We know which cartoon had the greatest catch phrase of all time.
Without a doubt, it would be....
The Smurfs. You smurfing well know they had the smurfing best smurfing catch phrase in all tv-dom. If I wrre not so smurfing stupid, I might even have a smurfing chance of remembering what the smurf it was. That would be smurfy. Oh, well. Trust me, whatever their catch phrase was, it was so smurfing awesome that it wins the contest.