The debate has been raging and continues to rage: Trent Richardson or Morris Claiborne. While the Bucs are almost certainly discussing those options, that may not be relevant: it's entirely possible that either Richardson or Claiborne is off the board once the Bucs get to their pick.
This is what Mel Kiper thinks will happen, as evidenced by his latest mock draft. He has the Cleveland Browns selecting Trent Richardson with the fourth overall pick, leaving the Bucs with Morris Claiborne as the only real choice. This scenario is becoming increasingly common, and it makes some sense: the Browns have a few good cornerbacks, including 2010 first-rounder Joe Haden. They don't have anyone at running back, however, and Richardson would immediately fill a big hole.
Morris Claiborne, CB, LSU
A great player, an instinctive corner, a high-character kid and a guy who can make a sagging pass defense better from the day they draft him. What's not to like? Claiborne is hands down the best cover corner available in the draft, and the Bucs still need plenty of help with age and uncertainty dotting their secondary. This is a safe pick and a guy who should be very good for a long time.