Coit Tower, in Nob Hill, has spectacular views. The top of Pacific Heights is another good option.

I recommend the following:
Pacific Heights
Telegraph hill (Coit Tower)
Randal Park (Ashbury terrace bordering on the Castro)
Potrero Hill, 20th and Wisconsin St.
Sea Cliff

Have fun!

from the top of Twin Peaks, right in the center of the city, you'll have great views of the entire spread of the city and its layout, looking northeast down Market Street, north to the Golden Gate, east across the bay, and west to the ocean. A bit further afield, also consider San Bruno Mountain to the south (great views of the city and the bay) or the top of Conzelman Drive just across the Golden Gate Bridge in the Marin Headlands for great views looking back to SF.

from the top of Twin Peaks, right in the center of the city, you'll have great views of the entire spread of the city and its layout, looking northeast down Market Street, north to the Golden Gate, east across the bay, and west to the ocean. A bit further afield, also consider San Bruno Mountain to the south (great views of the city and the bay) or the top of Conzelman Drive just across the Golden Gate Bridge in the Marin Headlands for great views looking back to SF.

Twin Peaks