Consider going to Cafe Salina (Millbrae near the airport), ideally on a Friday lunch for dim sum in addition. It’s a HK cafe but the dim sum master there who came out of retirement, does things right for the most part. Save sufficient room for their desserts, many of which went almost extinct as nobody else bothered to learn how to make them (e.g. black sesame rolls, baked sago pudding) and they do it very well (you can see their selection in the refrigerator case near the cashier).
Definitely hit up Ming Kee dine in rice plates. Soy sauce chicken (regular farmed non free range which are softer and plumper) is a must, and if you do empress chicken get the free range version. Cha siu is on the sweeter side but when you eat it with the ginger scallion sauce it blows it up (and a mouthful of rice together). Can also order some other roasties a la carte to try on the side. Last time I had the duck ,the skin was good, but not much meat…lots of bones (and this is the thigh). You may want to try squeezing in two visits just to taste a variety.
If you can get a reservation at Californios, I’d say go for it. If you liked and have been to Taco Maria, Californios really steps it up further.
I enjoyed Slanted Door back in the day, but personally would rather save quota to eat at other restaurants. You could try the pasta tasting menu at Flour + Water, the charcuterie, pizza, and proteins at Pausa (downtown San Mateo), try for a reservation at Sushi Yoshizumi also in downtown San Mateo (they are probably fully booked for two at the moment since they book a month ahead) or see if you get lucky with a cancellation and just go for the basic omakase, Sorrel for California French/Italian (Italian at its core but French sensibilities in the fine dining approach) instead of Perbacco.
Or replace one of the options with Maum.
If you can manage it, hit up Pho Y 1, East Capitol Expressway in San Jose (it’s further south from Winchester Mystery House). Arguably our best pho around where the broth is clean, natural tasting, and complex, you can taste all of the natural beef flavors, and if you get crunchy flank (ve dong) or their meatballs on the side, it comes in a very concentrated consomme that is ridiculously good. Having tried one of the Pho 79’s in Garden Grove back in January, I can honestly say Pho Y 1 runs circles around it easily. Even their cafe sua da on a good day is a touch hazelnut, aromatic, not over roasted (although can be strong). Though right now it’s roasting in the high 90s there.