I've been to most of the AYCE sushi bars Las Vegas has to offer and Sushi Koma remains at the top of my list. The fish here is very fresh and the sushi chefs do a great job at enhancing the flavor of the fish rather than depleting it. The servers and chefs are all very kind and always leave us with an overall wonderful experience.
As a side note, the restaurant is fairly small so be wise if you plan on attending with a large group. Also on the plus side, they're open late!