Bosa, Ezekiel, and outside linebacker Darron Lee. I've got all three at the top of their positions among underclassman for 2016.
Bosa with the widest gap between himself and #2 at his position (Emmanuel Ogbah). Ezekiel edges out Derrick Henry for the top RB spot. Darron Lee edges out Myles Jack.
Cardale Jones has mega-elite physical tools and characteristics, but 3 games of experience just isn't enough to draw any sort of conclusion on what type of quarterback he is. I see the 6'5", 250 pound frame, a bazooka arm, mobility, and a bunch of handoffs to a stud running back. One read and take off when he's passing the ball. But it gets there in a hurry when he turns it loose.
We don't even know that he's the best quarterback on his own team yet. He was #3 on the depth chart for a reason despite years in the program. Gets confused by the most basic coverages very easily at this early stage.
J.T. Barrett is a different story. I was sold on him. I have him as my #3 underclassman quarterback as a redshirt sophomore next year.