OK I have a few more P-type basses, only one of which is a Fender, and thinking about it they all have different strings on.
1. 1966 Fender - Fender 7150L Pure Nickel strings, they are a few years old now and mellowing nicely
2. Bacchus Woodline Classic P - D'Addario EXL170BTs
3. ACG Finn P (32" scale) - D'Addario ETB92M black tapewounds
4. Spector Euro LE4 1977 - D'Addario nickels, lighter set than on the Bacchus
I like them all for different reasons but I do stick the EXL170BTs on pretty much all my other fretted basses so I guess they are my favourites.