My sister & I recently spent a week in Sayulita and enjoyed the food offerings.
El Cameron (on the beach) amazing Aztec soup (avacado, chicken, cheese and tortillas) and a great veggie salad with lime dressing.
Rollie's near the town square - salads ok, salsa wonderful as was the paella and the chocolate souffle cake which melted in our mouths.
Sayulita Cafe - chiles rellano stuffed with raisins, peppers and cheese - great and a chicken mole that I am trying to reproduce at home with no luck (I live in NH. It was spicy, yet mellow with just the right amount of sweetness. Truly wonderful.
Argentinian Restaurant on the town square had good salads. My favotire was a cabbage salad with walnuts, roquefort and balsamic dressing. How that is Argentinian, I am not sure, but it was very good.
Sayulita Fish Taco (also on the town square)excellent!
Don Pedros - very good but not necessarily worth the cost. Great location right on the beach and flirty waiters.
Some of the best meals we had were from street vendors - one by the bridge sold me an incredible beef burrito and the "tamale lady" on the beach sold great snacks. We also enjoyed the nut guy who walked around the beach with a wheel barrow selling nuts and candy.
We spent one night in Puerto Vallarta and had dinner at the River Cafe which was very good. We had dessert at a latin/asian fusion place - something Bento. I had a passionfruit souffle that was amazing.
All and all, good eats.