Mine was Sly, because of the absurdity of some of the missions he does.

EDIT: I mean mascots introduced by Sony during the PS2 era, ok?

Crash.

Sony didn't introduce him in the PS2 era.

I dont think there was any crash exclusive ps2 game.                                                                                                                                                             

Says nothing about introduction. Crash had like 4 games on PS2.

Over all, I'd say Ratchet and Clank have been the most consistent great titles, been playing the recent one a lot lately. I would love a fifth Sly game as Thieves in Time was my favorite since the brilliant original.

I loved Jak 1, but the sequels did nothing for me and gave up on the series.

See, that's the beauty of Crash. He was so mascotty in PS1 era that it counts for PS2 as well.

Good question. I would say Jak and Daxter, but only limited to Precursor Legacy. Jak is a lot less likable in 2 and 3. So I guess overall I'd give it to Ratchet and Clank.

Amaterasu from Ōkami

R&C, easily. Had (still does have) the best games of the 3.