The Power Rangers have had a long history, traversing time, galaxies and jungles -- as well as changes in cast and the ownership of the franchise. And yet, through it all, they seem to hold more or less the same basic pose. Here are the iterations of the colorful heroes from the first season to the 18th. Saban's "Mighty Morphin Power Rangers," above, kicked off as a kids' show about a group of teens given special morphing powers to battle an evil sorceress named Rita Repulsa. It premiered on Fox and rocketed to No.1 in the ratings virtually overnight.