The two most well known buffet restaurants in Bellevue are probably the Eating Factory and Todai. And I think the Eating Factory is definitely better than Todai.
Located in a little shopping plaze on NE 8th Street, the Eating Factory might be easier to miss if you didn't see their not-so-big sign by the street. But if you do find the place, you'll find a good selection of sushi, rolls, chinese cooked dishes and desserts. Although its selection might be slightly smaller than Todai's, most of their dishes tastes a lot better and fresher. The price is also $2 cheaper than Todai's.