Kaizoku Sentai Goukaiger (2011)

Boukenger and Gokaiger celebrate the anniversary of the Super Sentai franchise. Their plots revolve around an adventure to search for valuable things: the Precious for Boukengers and the Greater Powers for Goukaigers.

After Tokumei Sentai Go-Busters, Kyoryuger is a return to the colorful fun of Gokaiger. There are an abundance of things to keep your eyes captivated and this really is the first sentai series I've seen post-Gokaiger to sort of capture the fun and spirit of it.

It's the 34th sequel of the series from Super Sentai right after Tensou Sentai Goseiger which is the 33th sequel. If you would like to watch the super sentai series chronologically.

It's the 35th sequel of the series from Super Sentai right after Kaizoku Sentai Goukaiger which is the 34th sequel. If you would like to watch the super sentai series chronologically.

Both are seasons of Super Sentai that have a heavy focus on being the anniversary of the franchise. Both seasons have a focus on Super Sentai being part of the bigger world/multiverse. Rangers can use the power of the previous seasons but having the gimmick corresponding to that season.

Both are seasons of a Toei tokusatsu franchise: Gokiager for Super Sentai and Zi-O for Kamen Rider. They have a heavy focus on being the anniversary of the franchise. Both seasons have a focus on the franchise being part of the bigger world/multiverse. Both seasons have many cameos of actors of the previous season of their franchise and both seasons' serve as a way to have continuations of the story for of these seasons. They also have a gimmick that has the power of those seasons stored in them.

Both are shows about transforming into past heroes
Both appeared in Kamen Rider × Super Sentai: Super Hero Taisen

It's the very first Super Sentai series what made many of it's successors possible. If you want to watch the original first season of the Super Sentai series.