Hmm, You guy's could all be right but base stat wise, Arceus is the strongest pokemon ever with 720 base stat. second is all tied with mewtwo hooh lugia rayquaza dialga palkia and giratina both forms with a base stat of 680. But if your on about non legendaries base stat wise would be Slaking with 670 and dragonite with 600. But slaking has that anoying ability truant which means slaking can only act every other turn, but by using the move skill swap to pull it away from him and ideally replacing it with something useful (such as levitate), you can turn him into a genuinely incredible attacker! but this will really only work on a 2 on 2 battle :/. In my opinion the generation 1 starter pokemon are great, Blastoise charizard and venusaur are great in heart gold and soul silver. With there amazing stats and if you teach venusaur earthquake you can take down them fire type's with no wings. But overall the best pokemon is defineatly arceus. But if you get the move's right and the battle going the right way even caterpie can be a lethal weapon! (not really caterpie) but yeah thanks for Listening to this longg paragraph and sorry for my spelling and caps and full stops but ya see ya ~POKEMON PROFESSOR STAR