they actually never did that big of a success on the PS2, it was mainly Jak and Daxter (Jak II) . Ratchet and Clank is second i think.
edit: and with sucess i meant Sales, the only place i knew about Sly cooper is from a secret demo in one of the games (forgot about it), its not known well.
same thing happened to me with Urban Chaos , since i only knew about it from a demo in Hitman blood money.