I can second the recommendation of Frascati . .

I will third the recommendation of Frascati. It was the dining highlight of my trip in July.

Some very neighborhood-centric recs:

Firefly, as mentioned above, has a prix fixe either Sun-Wed or Mon-Thurs, I can't recall which, for $35. Appetizer, entree, dessert and coffee. With tax and tip, you'll be above $70 for two, but it's a lovely, low-key restaurant with excellent food and gracious service. If you plan to visit Noe Valley, I'd go. The J Church muni line wil take you to 24th and Church. From there you can either walk up up up or take the...is it the 48? up 24th street.

Also, the 24 from the Castro will take you to 24th and Castro. Then it's a quick 2 or 3 blocks up to Firely.

Chenery Park may come in just at your budget depending on what you order. chenerypark.com. This location is very convenient to Glen Park BART station if you're staying near a BART station.

Delfina pizza in the mission. Always busy.

Pauline's Pizza on Valencia and 14th for innovative, gourmet pizza and salads. Funky and fun.

Food is actually pretty good at the cfafe in SFMOMA. I eat lunch there all the time because it's near my work.

If you would like to try Polish food for very reasonable prices, I highly recommend the Old Krakow Restaurant, 385 W. Portal Ave. 415-564-4848. It's a small place with a pleasant dining room, very friendly and attentive wait staff, and we absolutely love the food.

Oh, and as much as I love Chez Panisse, I think if I were trying to do something more casual in the East Bay, I'd take BART to Rockridge in Oakland and eat at A Cote. With careful ordering, and no booze drinking, dinner could be $70 for 2. I was just there with a friend and we spent under $50 each and shared a bottle of Malbec and dessert.

www.acoterestaurant.com

Hi!
One of our favorite SF restaurants is Khan Toke Thai House on Geary between 23rd and 24th Avenues. Doesn't look much from the outside but inside the whole place is teak panelled, the tables are low but you sit with your legs in a 'well' (not uncomfortably crosslegged!), the lighting is low, the servers seem to glide silently around the restaurant and at the back is a little Buddhist garden. Oh and the food is absolutely the best Thai in town! Do make sure your socks don't have holes as the first thing you have to do on entering the restaurant is take off your shoes and leave them with the shoe man! This is a dinner recommendation - can't remember the price ranges but not exhorbitant. Maybe the sfgate site lists that detail!
Enjoy!

My husband & I always enjoy Jeanne d' Arc, 715 Bush St, San Francisco, 94108 415.421.3154. This is a small restaurant in the Cornell Hotel that has a very reasonable, prix fixe dinner preparing classic French food. The restaurant puts one in mind of many small restaurants in Paris. Room + dinner packages are available through the Cornell Hotel.

One of my favorites was L'Osteria del forno at 519 Columbus which was well within your budget and quite delicious. Service wasn't great, but am going back to SF in Dec. with my "Italian daughter" and plan to take her there--and she's very picky when it comes to Italian food (took cooking classes in Siena.)

Also, for a very inexpensive and healthy lunch try Andale Taqueria at 2150 Chestnut.

Also well within your budget and good was The Helmand at 430 Broadway--Afghani food and Utopia Cafe at 130 Waverly Pl. for Chinese.

Let us know where you go and how it was. Have a great trip.

I live in the Bay Area. Here is what I recommend:

1. dinner for 2 - approx. $100
1. Bar Tartine-- Mission- California cuisine. Reserve 1 month out.
2. Delfina-- Mission--California cuisine. Need to reserve at least 1 month in advance. Also, they serve lunch in their next door pizza type cafe-great and reasonable.
3. Chez Papa or Chez Mama-- Potrero Hill. French food. Hip restaurants, Chez Mama is the less formal version of Chez Papa.
4. Range--California cuisine-Mission. Great food and service.

All choices do have great wine lists if you desire a glass.

Without alcohol, you should have no problem staying w/in budget and you will enjoy yourselves.

I forgot, if you go to the East Bay ie, Oakland area where Chez Panisse is, try the following as less stuffy alternatives:

1. Sea Salt-fabulous new sea food restaurant on San Pablo avenue-fantastic!
2. Cesar-2 doors down from Chez Panisse-fun crowd; tapas and drinks. Great to go on a clement day-their front windows open onto the street-it's a lot of fun.
3. Dopo--good Italian joint in the Piedmont area of Oakland.

The OP might have already taken this trip by now...but since the thread's alive again, I'll throw in my two cents -- if you eat at Boudin Bakery, keep in mind that you can eat at the a la carte cafe downstairs much cheaper than in the dining room upstairs. A bread bowl that's $15 upstairs (plus tip) is $8 downstairs. Yum :)

I'd love to hear more if there are any not already mentioned. We're going back in a few days and it's always good to get current advide from Fodorites.

I live in the Bay Area, too (part time, that is) and I recommend, ALWAYS, Delfina to those looking for good food. However, it is not purely California cuisine as was stated by an earlier poster - it is more Italian/Florentine with a slight California touch.

The grilled calamari on white beans is a signature dish, as well as one of the best Trippa a la Fiorentina ourtside of Florence.

I can still tell you the exact date when we ate at Delfina, as it wasn't anything like we expected.

Despite being considered the real "in" spot, it was more than half empty. About half the waiters and none of the bartenders showed up for work that night and it was chaotic to say the least -- thank goodness there weren't many people there or it would have been impossible. It took nearly an hour for our food to arrive at the table, the kitchen was very short staffed. What I first ordered couldn't be prepared, as a delivery hadn't been made that day. The mood was somber.

All is forgiven. It was September 11, 2001.