Get Pride FC for the PS2. It has Ken Shamrock in it (since you asked), and it also happens to be the best MMA game out there.
It doesn't matter if you agree or disagree
... As long as I don't bore you and I spark a moment of thought, my goal is achieved
Queng leon queng tigre ecu tacacut, queca pa? - Pampangan Mandarigma Motto