SB Nation.com has been creating some lovely graphic representations of each NFL team's needs, and they have one for the Tampa Bay Buccaneers, too. With a screaming Greg Schiano. He does do a really good scream face.
Tight end is the only true need for the Buccaneers. Luke Stocker and Tom Crabtree are nice second and third tight ends, but they're still missing someone who can be a real threat in the passing game. While the Bucs' offense doesn't rely heavily on the tight end, it is still a valuable and useful position and one that needs to be filled at some point this offseason.
Most of the other positions in yellow just need more backups. Cornerback? The Bucs need a nickel corner. Defensive line? Some depth would be very, very nice as they simply don't have any at this point. One injury and they're back to starting Daniel Te'o-Nesheim. He's fine as a backup, but you don't want him on the field too much. Offensive tackle? One injury to either Donald Penn or Demar Dotson and the Bucs are screwed. Quarterback? Freeman's entering the final year of his contract. The Bucs need some insurance there.