Out of the marvel characters, I have to say Vision is striking me as the strongest. His eye beam can clear a room within seconds
For Star Wars I'm torn between Vader and Kylo Ren. Vader's got the brawn but Ren's ability to stop time is really neat
With the Disney Originals I'm not sure who that designation could go to, but I'm leaning towards Maleficent due to how she's able to stun you in the air and heal herself.
That's just might thoughts, what about you all?