Coples.
This thread started as a "Coples is going to be a monster" post. Guy was already one of the best players on the D last year, though there was less competition than usual.
The best case scenario is that John Idzik is the Jets' 2013 MVP.
Players improve, the team wins, and he will get his praise. He absolutely has to nail the draft, hopefully with more picks than they already have.
Hill is the only guy on the team with any upside worth talking about. MAYBE Jeff Cumberland.

Depends on how you define breakout...like breakout as a pro bowl
caliber player or breakout into a solid starter? I'm not sure there is a
hidden pro bowler on the roster (maybe one of the DLmen, though Mo Wilk
got robbed of the probowl this season).
As far as just solid starters - Davis, Vlad, Powell, Cumberland - all
come to mind as player who we could end up being nice surprises as
solid starters. Maybe McIntyre. Not sure if you'd consider Kerley to
already have a breakout year, but I could see him having a 70+ 1,000
yard season with a decent QB. I've got no faith in Hill ever learning
how to play Football.
Yeah, as I was listing them I kept thinking "breakout relative to their individual talent." Someone like Coples can breakout into a Pro Bowl type player while a Clyde Gates type talent is just going to carve a little niche out for himself on the roster until something bigger/better comes along.
I'm not sure what I think of Hill beyond "he's still a freak athlete, very young, and has never seen a quality QB." A smart coach and a good QB can make use of a guy like this, but yeah....yeah.