You may choose to live in downtown Sanfransisco, south Sanfransisco or Daily city area. It is not advisable to live in and around Oakland side since you will be paying bridge toll every day when you drive to work. You can even live in and around San Mateo or San Carlos area if you like to drive 15-20 miles to work everyday during rush hour traffic. You may find apartments slightly cheaper there as compared to Sanfransisco though. By the way, i used to live in Bay area some time ago but now i live about 600 miles north from Sanfransisco. Enjoy your stay at Sanfransisco.