There are not a lot of restaurants in Twin Peaks proper, but some of San Francisco's best restaurants are next door in Noe Valley. Here is a sampling:
Firefly: (Some people think this is the best restaurant in SF, but be sure to check your credit before you come here Vick.)
Lupa: A great Italian joint.
Contigo: A tapas bar.
Le Zinc: A French joint.
and Hamano: a sushi place.
The only place that I know of in Twin Peaks proper that is worth going to is
Chan Chan, which sounds like it is a corny Chinese place but is actually a Cuban place--go figure!