Bonzai is a trendy little restaurant down in Pioneer Square. As the name suggests, it serves Asian (mostly Japanese) food. Anyone familiar with Wasabi Bistro up in Belltown should recognize similarity in their style, menus selection, and price range because they share the same ownership and target audience.
Their food definitely pricier than your average sushi bar, but they also do have one of the more creative/non-traditional menus, eg. "Las Vegas Roll", a deep fried eel, crab, avocado, cream cheese sushi roll. A full menu can be found on their website at http://www.bonzaibistro.com/web0804/sushi.html.
Bonzai is very conveniently located within 5-10 minute walking distance of Safeco and Qwest Field, so definitely make it one of your stops when down in the Pioneer Square area.