If you ever get transported to one of these anime, make sure you're on the side of the protagonists. You definitely don't want to go up against any of them, because the main characters on this list are virtually impossible to defeat.
There's Alucard, the superpowered vampire/vampire hunter from Hellsing. There's Rimuru Tempest of That Time I Got Reincarnated as a Slime, who started off as a powerless slime before ramping up his power so far that he became nearly unbeatable. And of course, there's Saitama, who gained the ability to wipe out anybody with a single punch after a comprehensive workout program.
These characters, and others like them, are proof that supreme power doesn't mean a lack of stakes or conflict. These high-powered characters build tension not by whether they'll defeat their opponents - they probably will - but by what outlandish ability they'll use to do it. Vote up the shows that excite you the most.