Visiting from NYC
Belden Place is a block long "restaurant row" that is no more than 2 blocks from the Triton Hotel. At least 5 worthwhile restaurants are located there:
Sam's Grill - Traditional, old-school seafood house
Tiramisu - Tuscan/Italian
Plouf - French seafood, w/excellent mussels
B44 - Spanish
Brindisi - Italian seafood
That's a rather broad question, as you will be in easy walking distance of Union Square, Chinatown, North Beach, Belden Place, Financial District, etc. Lunch or dinner? Price range? Cuisine? How Close?
Keep in mind, too, that SF is pretty compact and public transportation is good. You might want to restate your query and give us a few parameteres.