Sorry if this has been covered already, but I've looked around and not found any good references to a decent bowl of ramen in downtown SF (FiDi or nearby - I'll walk a few blocks!).
I was working in Emeryville until recently, and enjoyed Ryowa's ramen based on the recommendations here - having lived in Tokyo for two years, I tried quite a bit over there.
Also, what about good kara-age downtown? So far, the pickings are slim. Ozumo is OK, but overpriced and not very authentic.