The unpleasant area that you hear about in the news is basically just the border between districts 5 and 6 in this map: https://voterguide.sfelections.org/sites/default/files/image...

My knee-jerk answers for where to not stay are downtown, anything near the Tenderloin, anything in the mission close to a Bart station. Bayview/Hunters Point is also on that list, but no one accidentally stays there.