Hah quite a question, SB is literally full of amazing places to eat
Breakfast at the Harbor Inn out on the pier in SB is good for the ambience and atmosphere especially as the lunch and dinner offerings are a little disappointing and over-priced compared to what else is on offer in town. Though I had an amazing breakfast recently at Eladio's on the corner of State and Cabrillo Blvd (at the base of the pier).
Enterprise Fish Co at the bottom of State St is really good food especially for happy hour. Other noteworthy places would be Opal Restaurant at the top of State St, Holdrens for steak/ribs type food, Arigato has amazing sushi but is pricey, er.. the list goes on

Oh El Paseo is a cool Mexican place as it's kinda in a courtyard which is open air and they have live bands and strong margaritas

Tbh I've lived here for 2 years and there are still plenty of places I have been told are good that I haven't got to yet.
Yeah that place in Avila is awesome

Otherwise San Luis Obispo is a cool little town with some good bars and burger joints, don't know enough to recommend fine dining to be honest