Venusaur

When Venusaur was first dropped into the UU tier, nobody could've foreseen how dominant he was destined to become. He has just the right stat distribution and movepool to excel as a bulky sweeper; notable features include complementary STAB moves in Sludge Bomb and Leaf Storm, semi-reliable recovery in Synthesis, and the ability to instantly disable an opposing Pokemon with Sleep Powder. Not only this, but Venusaur also has a plethora of other options and the stats to make use of them; he can run defensive, physical, and mixed sets effectively as well. Despite these attributes, Venusaur's middling Speed and predictable coverage ensure that he is far from uncounterable. By no means, however, should this top-tier threat be overlooked.