Bar Masa is in the Aria. It is very expensive and has very fine Japanese food (if you want cheap sushi there are a hundred other places to go). Quality sushi is not common in the US so many people don't appreciate it, but if you do you will love Bar Masa. For example, uni (sea urchin). I've tried this at many Japanese restaurants, and universally, it made me gag. Literally. That is, until I had the uni at barMASA. At barMASA the uni is creamy, tasty, and delicious. My only explanation is because the ingredients are really fresh and well prepared. A lot of the other items on the menu gave me similar experiences. "Toro" in a lot of restaurants suspiciously tastes just like regular tuna, but here it's rich and delicious. Octopus is often chewy and kind of tasteless, but here the hibachi octopus is perfectly cooked, tender, and tasty (they put some kind of sauce on it that is really delicious).