So this is an alternate storyline that I've made in which Goku dies on Namek.
Son Goku is unable to find a working space ship to escape Namek's destruction, he resigns himself to his faith as he watches the planet about to detonate. With one fiery yell of discontent, Goku and the planet go up in smoke. He dies as the "strongest fighter in the universe" and sets a new level of power for his friends to meet.
Son's friends try to revive him using the dragon ball but are told that he will just die in space, since there is no planet. Goku comforts his friends that he is fine being dead and that he will meet them some day in the afterlife, he urges all of them to get stronger for future threats that may arise. With no Goku to wait on, Vegeta initially leaves Earth to train in outer space but finds that there is no one that can really give him a challenge and he has plateaued in his progression. He returns to Earth and demands that Dr. Brief construct a gravity machine for him that is 5x as tough than Goku's own in order to surpass him. Fast forward 1 year from now and Frieza and company arrive on earth to seek revenge on Goku. Trunks from an alternate timeline, in which Goku escaped Namek but died of the heart virus, intervenes and kills both Frieza , his father and all his men. He then informs everyone that he is from the future and came back to the past to find out information on how to stop the coming androids that are set to arrive in 3 years.
The androids attack Amenbo island. The Z senshi arrive and things play out as they did in the original manga. The only difference being that Piccolo fights android 19 and is saved by Vegeta, who then reveals that he is now a legendary SSJ. Andriod 20 flees the battle to get to his laboratory, and activates 16, 17, and 18. Everything continues to play out as in the original manga, with everyone losing to 17 and 18, while 16 watches the battle. After being informed by krillin, that Son Goku died on Namek, the androids choose to leave and find their purpose in life. Krillin then uses the senzu beans to revive the others and inform them on what happened. Piccolo is shaken by their power and goes to Kami to fuse with him. Vegeta flies off in disgrace, having been bested as a SSJ. At Kami, Piccolo arrives and is informed by Kami of another entity from the future. He agrees to fuse with him and they fly off to face cell.
Piccolo locks in on Cell's ki and confronts him at Gingerbread town, the fight between the two plays out like in the original manga. Vegeta and company sense Piccolo's ki and race the scene to find out what is going on. Piccolo informs them of this new entity and how they must stop it from absorbing the other androids. Using Kami's knowledge, Piccolo informs the others of the time chamber and urges trunks and vegeta to go in first, while the rest of them hunt for cell. Cell however is smart and hides his energy signature, he slowly builds up his power by killing people across multiple towns until he is confident that he can fight the androids. He eventually spots them, when their whereabout are reported on the news for a crime that they committed. Cell confronts the androids and begin fighting them, Piccolo senses his ki and correctly deduces that he must have found the androids. He race to the area and forms a temporary truce with 17 to stop cell from becoming perfect. Unfortunately, both are defeated and despite 16's best effort, cell becomes semi-perfect. The rest plays out similar to the manga, in which Tien holds off cell to give 16 and 18 a chance to escape. Unfortunately for Tien in this alternate universe, he is killed by cell but Piccolo manages to barely survive and is saved by Gohan, who was sensing the battle on Kami's lookout.
From this point forth, the story plays out similar to the manga, with Vegeta and Trunks confronting cell but ultimately failing to stop him from becoming perfect, as well as, Dende becoming new guardian of earth. Gohan and Piccolo go into the time chamber and Piccolo being aware of Gohan's hidden potential, pushes him towards becoming a SSJ and utilizing his rage. After ~ 1 day has passed, Piccolo and Gohan emerge from the time chamber, stronger than ever. They are informed of Vegeta failing to stop cell and of the upcoming cell games. Piccolo continue to train with Gohan during the coming days that lead into the cell game. On the day of the cell game, Gohan fights Cell and puts up a decent fight similar to Son Goku. Piccolo urges him to unleash his hidden power but due to Gohan fear of his power and gently nature, he resist. Cell wanting to find out more of Gohan's hidden potential unleashes the cell jr. on the z-senshi. This ultimately leads to the death of Android 16, which pushes Gohan to SSJ2. At this point, it plays out similar to the manga with Gohan defeating cell as a SSJ2.
Cell ultimately resorts to suicide via self detonation but is stopped by Trunks, who quickly picks him up and carries him to space to prevent the planet destruction. Trunks is killed in the blast but cell survives and reforms as Super Perfect Cell. He then returns to earth to gloat about his new power and Trunk's death. This enrages Vegeta, who subconsciously has grown attached to his future son and he launches an all out attack against Cell. This fails and cells knocks away vegeta, ultimately leading to Gohan getting injured. The rest of the events playing out similar to the manga. After cell is defeated, Dende uses the dragon ball to revive Tien, Trunks and everyone else killed by Cell. Trunks returns to his timeline in the future and peace is maintain in the world for the next 7 years.
