>>48232903Around gen 4 or 5, some guy (probably on reddit!) made a huge in-depth comparison of pretty much every single mon released at the time to determine who the strongest really was.
Essentially, he looked at every moveset a pokemon could have and squared them up against every other pokemon (sounds ridiculous, I know). Ultimately, the winner would be determined if there was a moveset that would always create a win -- that is, the opposing pokemon would always lose to this moveset.
In the end, there was a tie for 1st place of who the strongest pokemon was:
Arceus and Mewtwo.
God, and manmade god. In-game, there was always a moveset the other could have that would trounce the other. There was never a clear-cut winner. But they were tied for first. Pretty based.