Shiftry, for obvious reasons regarding my name... lol.
I love that it's such a strong and fast pokemon and it has the movepool to completely destroy fire types with rockslide, especially if they use sunny day (passive ability is chlorophyll: double speed in sun). It can learn swordsdance to amp it's already ridiculous ATK stat, it can use knock off, leafblade and suckerpunch to sweep teams. It even looks like a boss. Shiftry is a scary pokemon to face in the games and would be even more tricky to face in the anime world.