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?
Apart from the trophies he won at Roma he didn’t win anything with Roma…I hate these types of mental gymnastics, he either won things or didn’t, which he did, he won a league title ffs.
Someone of Totti’s ilk that stands head and shoulders above him as a one club man is Steven Gerrard, the man dragged Liverpool to most of the trophies he won there in teams that wouldn’t have gotten near any trophies without him. They wouldn’t have even qualified for the CL, let alone get out the group and go on to win it in 2005 without him.