I stayed in The Mosser last year, it's a little old fashioned (eg. thin doors, but modern locks). but cheap and cheerful. You'll probably want an en-suite bathroom but I was travelling alone and the shared bathroom was perfectly adequate, I always had use of one when I needed it. The rooms were a little small, but it's a going-out hotel not a staying in/convention hotel. It's in a great location, just a two minute walk to the cable car turn-around off Market St.