Well, there's no doubt about lunch, it would be at the Tadich. Even before moving here that had to be the first place I visited for lunch. Now, dinner, hmmmmm, Boulevard is a favorite that's for sure and always has been.
If cost was no object, a dinner with Ron Siegel at the Ritz would be pretty close to the top of the list. I would also have to consider Le Folie.
Let's face it, it's just a really tough question for those that have lived and eaten here for many years. Little neighborhood places like Luella and Rue Saint Jacque are excellent.
I guess it's just not a choice I want to have to make.
IMO, Zuni and Delfina both outclass Canteen. Canteen is a fun restaurant and I would recommend it heartily to locals who are tired of the "scene" or need a new place to eat, but in terms of overall experience Zuni or Delfina are superior. I haven't been to Blvd, but only because it gets such mixed reviews and is very very expensive compared to other SF restaurants.
EDIT: but I would definitely do Canteen for lunch or breakfast over almost any restaurant in town. The above comments apply to dinner.
Plouf is fun, but only go if you love mussels and fries.
Piperade would be a fun substitution for one on your list. Basque style tapas; fairly unique and well executed. Get the sheep's milk terrine and almond mousse for dessert! Aziza is fun, but I don't find myself dying to return. If you like/have never tried Moroccan, keep it in mind.
But honestly, I've been away from SF for about a month now, and of all the restaurants anyone has listed so far, I find myself missing Zuni and Delfina the most (Delfina was actually my last dinner in town, that's how much I liked it).
i would do pizzeria delfina for lunch instead of delfina for dinner. for a great cal-italian meal do aquerello. ive just never felt i get what i pay for at delfina. for slightly more traditional but still cal influenced, go for Incanto.
instead of boulevard i agree you should either go to Myth or just bite the bullet and eat at the ritz.
zuni. yes. i love zuni.
if you get your italian needs satiated by the pizzeria delfina lunch you should go to aziza instead of one delfina aquerello or incanto.
It really depends on where you are coming from (Literally, not as a figure of speach) but my initial thought was that your list is solid but not varied enugh. A little, well, predictable.
I'd definitely substitute Azizza for one of the three (probably Zuni, but that's just me), as it is unlikely you have anything similar whereever you are from. I recently took a colleague from Manhattan; he loved it.
Also give some thought to Piperade and Canteen. I'd rather go to Myth than Boulevard (though it has been some months since I've been to either), and Myth is cheaper besides. Another option that might appeal to you given the bent of your choices would be to get on BART and go over to Berkeley to Chez Panisse. Definitely worth considering. I'd also add in some high end Hong Kong style seafood..
hmm...guess you need to add in a few lunches too. :-)
I second the Canteen suggestion. Try to get the late seating so you don't feel rushed.
I always take out of town guests to Plouf, because I like the atmosphere of Belden Place, and it's hard to go wrong with moules frites. It might make a good lunch choice if you're visiting during the week.