There are plenty of great options: Giggs, Scholes, Baresi, Maldini, Facchetti, Puyol, etc.
For me though, the greatest is Francesco Totti. The others above played for clubs who won multiple trophies, and all won the champions league at least once. Aside from a smattering of Coppa Italias and one Scudetto, Totti didn’t win anything with Rome.
For me, it’s easier for a top player to stay at a top club, rather than be a top player like Totti and stay at a club that was rarely considered the best in Serie A. For my money, he is the greatest one-club man of all time.
Who would you choose?
If Rogerio Ceni had played for a European club, no one would even be having this discussion here. The man scored almost half of Totti’s goals as a goalkeeper and played more for São Paulo than any player for any club. And I’m a supporter of a rival team.
If Rogerio had played for Arsenal ou Man Utd he would be the GOAT goalkeeper alongside Neuer and Buffon, and nobody would even think twice.