In Santa Paula I recommend El Pescador on Peck Road and Telegraph, close to the free entrance. There is also a branch in Filmore right on Hwy 126, but I haven't visited it. All the branches are owned by the same family. I usually get the fish tacos, my SO likes the carnitas, and they have this huge special consisting of different grilled meats and nopales that is enough to feed two.
I noticed in a Travel section article in the LA Times this morning that they recommended this place called Rabalais' Bistro (Cajun & Creole "inspired" food) in Santa Paula. Found some Yelp reviews and a link to their website here: http://www.yelp.com/biz/rabalais-bist...
I haven't been so I can't give you any first hand info.