Kamen Rider Skyrider (1979)

Skyrider is the series after Stronger so if you want to watch the Kamen Rider seasons in order then watch Skyrider after Stronger.

These two have basically the same set up with a young man kidnapped by an evil organization that turn him into a cyborg to do evil with. Only to be freed by the one that upgrade then

Both are back to basics series with cool protagonists. Boonboomger has more interesting characters but that is because it is later but skyrider is still a good example of what these franchises are

Super-1 is the sequel to skyrider both feature riders who are cool and level headed. Super-1 more unique thing with it's multi hands and focus on marshal arts but both end up as a basic Kamen rider series