Gotta predict offense.  Either OL or WR would be my guess.  With Mike Williams being kinda iffy, they don't have much after VJax.
Edit to add: Another possibility would be a QB to groom while McCown is a stopgap.  Not enamored with that based on the reviews of the QBs so far.
		
		
	 
They're in a pretty good spot in most draft scenarios now after filling so many holes.  I would prefer Watkins or Evans, but one of the tackles would be nice as well, but do any of the LTs fit on the right side?  Maybe all 3 or at least 2 of the top QBs will be available and they can back up a few spots if Clowney, Watkins, Mack, and the tackles all get drafted 1-6?  That could really be a worst case scenario if nobody wants to move up for a QB.
It's hard for me to envision a QB being the pick.  Why go out in free agency and spend all this money adding starters only to break in a rookie at the most important position on the field?  A QB with that pick basically has to start right away.  That being said, all of the starters they added are 28 or younger, so there is some time to break in a young QB.  So, groom Glennon if that's the plan.  I don't see why any of these 3 players (Bortles, Bridgewater, Manziel) are head and shoulders better than him.  Draft a guy in the 5th.  They still need someone else.
Aaron Donald intrigues me.  He projects as a 3-technique tackle, and the Bucs obviously have one of those in Gerald McCoy, but if you're building a relentless pass rush he's the cream of the crop from the interior.  Mold the line after the Seahawks and just keep sending fresh players after the QB.