I loved "Nemuro Hanamaru" in the shopping mall KITTE. They are a conveyor belt type sushi restaurant but has the best quality of fish among restaurants in that style. They are originally from Hokkaido. There is always a long queue which means locals love this restaurant, too!
I would say Sukiyabashi Jiro is the one you need to visit while you are visiting Japan! It is hard to make a reservation, but it's worth paying money for it!