Out of the choices you listed, I picked He-Man. There seemed like endless worlds, people, and enemies to discover on Eternia. I liked that he wasn't always battling Skeletor, whereas the others save for maybe Thundercats seemed to have the same battle each week.
He-man had the variety on all levels to keep us intrigued. Did it have lame characters and episodes? Yeah, but all the others did as well.