This is single-handedly the best movie in the Dragon Ball franchise and it had nothing to do with Goku or Vegeta being the main characters. Instead, this is the story about the last days of The Saiyan Race within Universe 7, more specifically Goku and Raditz's father, Bardock. Bardock isn't the perfect father by any straight, he isn't there to visit Goku after the day he was born nor did he think he was special when he tested his power level, the same could be said for not caring or being there for Raditz ( He isn't in the movie). However, Bardock is a great warrior who deeply cares about his crew and fighting who one day during a mission is given the ability to see into the future, and what he sees horrifies and mystifies him, the destruction of the Saiyan race and the future of Goku on Earth
We see Frieza's paranoia of the Saiyan Race at an all-time high with Zarbon advising to Frieza that the Saiyans especially the lower class like Bardock could pose to be a huge threat one day. Frieza wastes no time in dispatching Dodoria to murder Bardock and his entire crew on the false pretense Frieza asked Bardock and his crew to go on a special mission to wipe out the inhabitants on Planet Meat
After realizing Frieza had set them up and saw the massacre of his crew as well as barely surviving an attack from Dodoria and his men, Bardock comes to the realization that Frieza will be the one to destroy the Saiyans by blowing Planet Vegeta. Bardock goes on a short path of redemption and despite knowing he will be long dead by the time Goku arrives on Earth and becomes a different warrior than him, Bardock attempts to face Frieza head-on with the hope that he may have a chance to change the future, while also regretting not being there for Goku and Raditz
In his final moments, as Frieza unleashes his Super Nova attack to destroy Bardock and everyone else on Planet Vegeta, Bardock has renewed hope that Goku will be the one to avenge him and their race by defeating Frieza. It is honestly a powerful and emotional Dragon Ball movie and Bardock's sacrifice is no different. This movie sets up the future showdown between Goku and Frieza, as well as Goku's earliest battles and adventures on Earth leading up to his fight with Vegeta as well.
