@anon158713-- I have tried several different ceviche recepies, my favorite is actually the Puerto Rican recipe. It has olive oil, cilantro and garlic in addition to the ingredients mentioned here. I'm not sure if this recipe is unique to PR, although it seemed so to me.
Nothing is comparable to the ceviche at Ceviche House in PR though. If you go there, make sure to stop by this restaurant and try ceviche.