My picks in no particular order:
Powerpuff Girls: The battles in this cartoon in general, highly resemble DB fights, and I think Buttercup in particular would fit in the best.
King from One Punch Man: Just replace Mister Satan with him. Imagine when Cell was defeated by Gohan, King somehow gets credit for it.
Doomfist from Overwatch: Level of power aside, he thematically would fit into DBZ. He would be a good villain for the franchise, and he has the mentality of a Saiyan. He loves to fight just for the sake of it and he has a very darwinistic philosophy, believing only the strong should survive. His goal in his respective universe is to plunge the world into war as he believes it will make humanity stronger.
Kazuya Mishima from Tekken: I don't have much of a good reason. He just looks like Vegeta.
Garou from One Punch Man: Basically just combine the reasons of Kazuya and Doomfist. Although he's not really darwinistic, but he's an interesting villain non-the-less. Again, I'm ignoring level of power here and just focusing on theme.
Spongebob: I would just be curious to see how he and Goku would interact on a friendly basis. Beerus would also probably demand Krabby Patty's from him, or threaten to destroy him. I imagine there would be friction between Beerus and Mr. Krabs too.




