I still haven't found a favorite sushi place in the Phoenix area yet, but this one is my go-to on Saturdays for lunch. Kona has a "happy hour" lunch, where select sushi rolls and other dishes are half-price!
Kona is at Scottsdale Fashion Square in Scottsdale, across from Starbucks and The Yard House. On the weekends I prefer to mosey up to the half-in, half-out bar upstairs on the patio and enjoy lunch. The dining room downstairs is nice also. The service has been great nearly every time I've been. So far my fave rolls are the Vegas, Bama, Voodoo, Crab Special, and the good ol' standbys, California and Philly.
If you're going on Saturdays and plan to sit at the bar or on the patio, I suggest arriving before noon -- very crowded after that.