Best food in the city while eating solo at the bar?

Check out the following

State Bird Provisions - very difficult to get a seat but amazing food

Hakkasan - Trendy Chinese food and they have great cocktails. Crispy duck salad is awesome.

Coqueta - on The Embarcadero a few blocks north of the Ferry Building. This is a Michael Chiarello restaurant. The food and drinks really are great. 

La Mar - Peruvian mainly seafood. Right near there is a bar called Hard Water which is a nice little trendy place

SPQR - Italian and great wine selection

RN74 - it is nice. I know they have a lounge, but not sure about a bar nice wine selection and great variety of food. 

Swan Oyster Depot

• Piccino (great wine, one of my favorite food spots in the city)
• Trick Dog (great cocktails, good food, trendy)
• Rosamunde Sausage Grill+ Toronado (cheapest option, more beer bar than anything)

There are more options but Ed has a great list on there.

To summarize, I have my favs in SF on a 4sq list:

• Umi
  
• Suppenküche
  
• Bourbon and Branch
  
• Roam Artisan Burgers
  
• Sweet Woodruff
  
• Bourbon Steak
  
• Presidio Social Club
  
• Lers Ros Thai
  
• Absinthe
  
• Bar Agricole
  
• Tony’s Pizza Napoletana
  
• Umami
  
• Yank Sing Restaurant
  

I go to SF for work and I just sat at the bar of Bar Crudo and had an amazing meal. If you like oysters, mussels, and amazingly fresh sashimi, this is a great spot. They have happy hour specials that start at 5 and it's pretty busy by 6 so try and get there early. Swan Oyster Depot is great too but it's only open until around 4:30 so it's not really a dinner spot. Lastly, Tadich Grill has been around forever, isn't far from the Financial District and is known for their Cioppino. All have good bar areas for the solo diner.

Nopa

Bar Tartine

Marlowe

Nojo Restaurant

Bar Agricole

Coqueta

Chaya (Japanese) and Hard Water (whiskey bar) by The Embarcadero are easy to get to, have great atmosphere, small plates and drinks

Everything that's been mentioned are great, since you're from LA and looking for a trendier vibe I would definitely say to check out:

Mas Sake Freestyle Sushi

The Brixton

Sabrosa

Check out Beretta in the Mission which has both a bar and a communal table, which is great for socializing while solo, and has some of the best food and cocktails in town.

Swan Oyster Depot for lunch!

Alioto's Restaurant off Embarcadero

You should check out Bar Agricole or Nopa, both great choices!!

Spruce in Presdio Heights

If you're in SF for business, I'm going to guess you're going to be in the Downtown / Financial district. In that area, (places with bar seating) I would suggest.

• Sens Restaurant in the Embarcadero. Mediterranean food. The bartender, Matt, is a great guy, and the view of the Embarcadero is fantastic.
  
• Ozumo just south of Market.  Japanese food. Nice bar area with happy hour specials on their grilled skewers.
  
• Barbacco@ 220 California St.  Italian food, always a popular lunch and happy hour spot. 
• Waterbar is trendy happy hour favorite, with $1 oyster specials from lunch until 530.  Great views of the bay.
  

Another suggestion (not in the Financial district) that is what I consider the ultimate bar style eating, would be  State Bird Provisions.  Reservations take forever for this Michelin starred joint, but since you're visiting, and I assume your schedule is flexible, get there on a non-weekend night, around 430, wait in line for about 30 mintues, get a seat at the chef's counter, or put your name down and come back at a later time.  The menu is constantly changing, and everything is good.  Make friends along the counter and share your food. 

Gary Danko

Lou's Fish Shack At Pier 47 - http://www.lousfishshacksf.com/

300 Jefferson St. San Francisco, CA 94133