We chose the Nob Hill Motor Inn at 1630 Pacific Avenue in the Russian Hill/Pacific Heights area due to its wonderful reviews on www.tripadvisor.com.
We were very pleased with our room: it had two queen beds, a table with two chairs, free wi-fi, in-room coffee maker with coffee, several lamps, working A/C and heat, refrigerator, microwave, TV with cable/HBO, FREE PARKING (miraculous in SFO), and the place was kept immaculately.
We paid $94 a night for the first three nights and $114 on the last (Friday) night.
However, the thing that makes this a true jewel are the motel's owners--especially Judy, who went above and beyond to assist us in every way imaginable during our stay.
http://www.staysf.com/nobhill/