I've been going to Vien for quite some time and it's the best place for a pedicure in northern Phoenix.
The staff is quiet, respectful, and clean. They have a TON of colors to choose from and will do designs and details for a minimal cost. They are professional, and their massage chairs work wonders to relax me.
They do a great job on the pedicures by massaging your feet and legs. I always come out of there feeling rejuvenated and relaxed - plus my pedicure lasts up to three weeks!
It's not the "fanciest" place to go to, but you get more than you pay for (and it's worth it!).