San Francisco is the standard for romance
I can not believe nobody included San Francisco in their romance stories. This city is known for it's literature writers and romantic settings. The foggy Golden Gate bridge exudes romance. The entire bay sets the moment for romance.
There have been many romantic songs written about San Francisco. The trolley cable leads more feelings of romance to the story. Look on T.V., there are commercials capitalizing on the romantic stage of the city. Double mint gum, rice r' roni, you name it.
Frank Sinatra one of the most romantic crooners loved San Francisco. The fisher man's wharf is the perfect place to take a romantic walk. When I visited San Francisco, me and my then wife went horse back riding in the Golden Gate park, that screams romance.
It has all the food items associated with romance like, Ghiradelli chocolate, Italian bread, oysters, lobster, clams, wine, you name it. I think I have laid out a good case for my choice, do the same for your choice. I write good review articles on several California cities at socaltravelhost.com