It certainly wasn't GI Joe! It was the coolest cartoon of the '80s.
I have the first two parts of the series on DVD. Looking back, while there are a few parts that definitely seem childish, the show dealt with a lot of more complex themes that you typically didn’t find in children’s fare back in the 80s.
It was a rare treasure to see that on TV. The novelizations of the series are rather fun to read as well.