Frieza Force

King Cold

Vegeta (Saiyan Saga)

Frieza

My personal bet

1. King Vegeta I was the King of the Saiyans during the Saiyan-Tuffle War and was the one who wiped the Tuffle Race out, not Vegeta III as is commonly depicted, he was also the one who the planet was named after after the Saiyans conquered the Planet Plant/Vegeta, he was also the son of the last King Sadala of Universe 7, who either was from Yamoshi's era or was the descendant of the King when Yamoshi was alive and kept the name Sadala even after their planet was long gone

2. King Vegeta II was the first one to officially begin the Saiyan's relationship with the Cold Force that Vegeta III then inherited, he also was the first one to co-opt Frieza-style armor for the Saiyans to replace their ancestral Sadalan Armor, perhaps also the one who put the Saiyan Power-Based Caste system into place with stolen Tuffle Technology being used to check a baby's power level that would then be replaced with the scouters in King Vegeta III's era as we see in the DBS Broly movie

3. I also like to think that Vegeta II may have had something to do with how King Cold and Frieza learned of the legends of the Super Saiyan and Super Saiyan God

Raditz

Zarbon

Cui

Ginyu Force