7.2 1975
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.
Choudenshi Bioman (1984)
Related
7.8 1997
Both have a evil scientist main villain
Both have a female pink and yellow ranger
Both yellow rangers are photographers
7.2 1983
It's the 7th sequel of the series from Super Sentai right after Kagaku Sentai Dynaman which is the 6th sequel. If you would like to watch the super sentai series chronologically.
7.5 1985
It's the 8th sequel of the series from Super Sentai right after Choudenshi Bioman which is the 7th sequel. If you would like to watch the super sentai series chronologically.