I believe that the Japanese Resturant in the Westin still has all you can eat Sushi for lunch, weekdays. It is not a buffet, it is served to you, fresh made and when I last ate there it was unlimited.

Additionally, the price was incredibly cheap. Like approx. $10.00 at last visit.

Check with the Westin.

Also believe that Todai is a Seattle-origin Buffet Japanese Resturant. We have one in Portland at Pioneer Place. Cost a couple of months ago was approx. $14 for week day lunch, $18 for dinner. Slightly higher on weekends. Excellent Sushi selection and absolutely all you can eat. Plus for the non-Sushiphiles, a vast selection of other Japanese items and desserts.

To check out location of Todai, you can use 411.com.