lmfao @ Mewtwo being the strongest. As if.
Anyways, there is no such thing. I've seen people pwn legendaries using anything from Skitty to Vespiquen, so needless to say, it's the trainer that makes his or her own Pokemon strong. You can use Mewtwo and Arceus in your team and still be defeated by someone using average Pokemon; it's happened before and will continue to happen in the future, lolo.
There isn't a strongest Pokemon, it's the way you train the Pokemon. I myself I have wiped out an Acreus with a Breloom and in a later match an Ampharos, this doesn't make them the strongest. This means I have trained them and use them in a manner which makes them stronger than others. There are plenty that could defeat them, so really, all are as strong each other in their own way. Sure, there are slightly weakerMagikarpbut they still have their own strengths.
Elite Four Karen said:Strong Pokémon. Weak Pokémon. That is only the selfish perception of people. Truly skilled Trainers should try to win with the Pokémon they love best. I like your style. You understand what's important. Go on--the Champion is waiting.
:cer_boogie: Once again, this awesome and timeless quote comes to mind:
Tiers are for queers! :cer_pissed: (can be applied to Pokemon as well, not just Smash Bros.)
Well, by the most objective way of gauging things, Arceus would be the strongest by virtue of having a godly BST of 720. XD
Personally, Snorlax is a beast. Not only is he bulky, he can put quite the hurt on nearly anyone with Earthquake and STAB'd Body Slam. XD