Sly would come out on top, he's simply the most beast of all the currents.
And I know, I just like saying it.
You think so? In a single combo sometimes or almost a single combo every other time, it's just much easier to fill Parappa's super meter. Either a forward square hit in any situation and then wait about half a second because of invincibility, or any combo that includes up square except for when used in a combo that includes both down square and forward square(since it pushes the character a little too far back,) and you can hit them without a chance for evade with Parappa's level one.