Been here for about 3 months now and been making a list of best things we've eaten.
Steak tartar: Spruce. Expensive restaurant with a reservation needed for a table weeks in advance but insider tip is eat at the bar and order the steak tartar and burger to split. You'll get out there for a decent price and the tartar is some of the best I've ever had. Served with these very soft, buttery, biscuits.
Tapas style filet: Chambers. Very cool bar setting underground in the Tenderloin. Records line the walls. The filet steak is served with a very hot rock that you cook each slice of the steak on yourself. Minute and half each side is medium rare.
Burrito: La Taqueria. Already been stated a bunch but order your burrito Dorado style. Gives it a very good crisp.
Chicken and Waffles: Hot Sauce and Panko to Go. Small korean shack in Nob Hill/Russian Hill area. Their wings are absolutely delicious. I recommend Chris's with the waffle combo. Also only place in town I've found Texas Pete.
Sandwiches: Boy's Deli (Polk St, Russian Hill). More for locals but my go-to sandwich shop. Dutch bread and very meaty. Hidden in the back of a market.
Ice Cream: Swensen's. Ghiradelli is good but for just delicious, more pure ice cream, Swensen's is the play.
Sangria: Lolo's. I'm not a huge Sangria fan but the GF loves this place and claims it's the best.