You've shown us some very powerful characters from well-known anime series. It's definitely a very difficult decision and one that's open to debate as to who would win. Saitama is supposed to win with a single blow, Goku is a being with great powers and abilities, and Satoru is a genius and prodigy from the day he was born. These three definitely have my attention, and I wonder who would win.
But what if we also add Zeus, the king of the gods from Record of Ragnarok? If you've seen that anime, you'll know that he has very powerful abilities and could be a rival to these three. Of course, this is just my opinion, and it doesn't take into account Son Jinwoo from Solo Leveling, who increases his abilities, speed, and power with each battle, making him a worthy and formidable opponent. Cheers!
Of course I've seen that anime! Zeus and a few others are truly powerful, but it was impossible to include them all. I also thought about Son Jin-Woo, and he might also deserve a spot on a top list. Ultimately, it all depends on the specific universe they're from and the strength of their opponents, because an enemy in one anime might not be as strong as one in another. It's all a matter of perspective.
Cheers!