Sony has a mascot for almost every genre but yes there are standout characters that are just popular from generation to generation.
Sonys motto is not to have a major mascot, but rather create characters for everyone. Be whoever you want to be.
In the PS1 era it was Crash Bandicoot, Spyro, Tomba, Parappa the Rapper, Sweet Tooth, Solid Snake, Cloud
PS2 era: Kratos, Ratchet & Clank, Jak & Daxter Sweet Tooth, Sly Cooper
PS3: Kratos, Nathan Drake, Cole Macgrath, Jak & Daxter, Rachet & Clank, Sweet Tooth, Sly Cooper, Sackboy
PS4: Knack, Delsin Rowe. More to come....