I have to start this post off by saying that the four stars is in relation to Phoenix sushi restaurants. It does not include some of my favorites in San Francisco, Hawaii or Vegas.
Stingray has become my favorite sushi joint in the Phoenix area. I can't wait for them to open at the Biltmore, so I don't have to make the trek to Scottsdale for decent sushi. The environment, with the only negative aspect being that it is too small inside. The food is very good as well. My personal favorite is the Spicy Special roll which comes out with a spicy mix of seafood on top (it changes and hence the special). Make sure to talk to your waitress about whatever they have fresh, but if you are a sushigoer then you should know this.
I'm a big fan of the bar area, and can be often found at the bar for some sushi and a few cocktails before a night out in Old Town. The atmosphere is great, the music is loud enough to hold a conversation, but not so soft that all you hear is the conversations around you. Their selection of Saki is good (not great), and the bartenders seem to be knowledgeable about the different brands. This is not a super high end Sushi restaurant like Sushi Roku, but they pack the punch of a good mid level sushi bar.
I am a big fan, and will definitely continue to frequent this restaurant.