Isobune in Japantown.
If you go here, be prepared to spend a lot of money! They have special gold plates that are $8.99 (usually lobster or something really fancy). I was pretty impressed with the salmon. The salmon was so creamy, it tasted like butter. Also, the eel handroll with avocado was amazing. I'll definitely go back, but only on special occassions where I can spend that kind of money.