I always preferred the She-Ra series to He-man.
It was a continuation of the He-man series, without it we would have seen a lot less of He-Man, Skeletor and co.,
It gave us some great backstory on some MOTU characters such as Skeletor's time with the Horde,
We got to see more of one of my favourite MOTU characters, Modulok,
She-Ra had better continuity and some killer crossovers with Hordak and Skeletor battling it out as well as politics and intrigue when Skeletor would form alliances with hordak's minions against him,
the bad guys were amazing and well worth watching the show for,
there was more scope for emotional storylines that I'm not ashamed to say touched me in ways that a MOTU episode never could (You wouldn't get He-Man crying for Skeletor like She-Ra does for Hordak for instance, that episode still gets me every time

),
There's just never been a cartoon series that has mattered to me in the same way that She-Ra does. the only ones that have even come close are Gargoyles and Swat Kats..