I'm not convinced SONY has a mascot of Mario's magnitude or Microsoft's Halo. Right now it's Kratos, and God of War. Past generations have shown that Playstation consoles are "adult" or "mature" consoles. Looking at PS1 I see Tomb Raider, Crash etc. PS2, I see great exclusives like SLY, Jak and Socom. PS3 assembled many great exclusives, Uncharted 1-3 come to mind, great thread OP.
PS1: Metal Gear Solid
PS2: Final Fantasy X
PS3: Nothing comes to mind at first, which is kind of telling, because I hated the PS3. And then I thought of some random niche games on there like Tales of Xillia, and thought... wow, that's kind of a dismal way to remember the system. So, Tales of Xillia.