Definitely Da Kine’s Plate Lunches at Liberty Station and World Famous in PB.
I was underwhelmed by El Indio on both visits.
Pacific Beach (PB) is not really for kids, it is a young adult area… bars, tattoo parlors, dudes tokin up on the beach. I’ve been to San Diego several times and usually stayed in PB at The Pacific Terrace (great place). When I told the woman at the car rental place that I was staying in PB, she responded “Oh, party boys!”