A safe, clean, easy-to-find place right in Central SF

I had to book a bed here last-minute because of a change of plans, and in retrospect I consider myself very lucky to have been able to do that because this place delivered in a huge way for me. A safe, clean, easy-to-find place right in central SF that is walkable to tons of points of interest and close to public transport for those a bit farther away? Plus a nice community area full of friendly staff and travelers with pretty good free wifi? And at a great value? This is a no-brainer for anyone who wants a very positive experience lodging experience at low cost.