Wolfgang Puck serves awesome sushi as does CA Grill. We've also tried Kimonos (at the Swan) and that was pretty darn good, too. In fact we'd go back and eat sushi at any one, if not all three, of these establishments.
Haven't tried the sushi bar at Kona - I've heard that it's good but their menu looks a little limited. If you're interested in a wide variety of sushi I'd suggest the other three restaurants.
Tokyo Dining had decent sushi but not on par with these other places in my opinion.