My vote is for Baggio. When you think of an Italian #10, you tend to think of a player that will bring you off the edge of your seat once he has the ball at his feet. DelPiero was more productive in regards to goals and titles, and is more of a Juve Legend, Totti has the hotter wife of the three, but for that sense of pure magic, to me the essence of an Italian #10, it is Baggio.
If you ask Italians all around the world whom they envision when they think of a #10, the majority will say Baggio. He is still fresh enough in the memories of a lot of people out there.