The best I've ever dealt with regarding passport photos. He made sure that the photos were flawless and met the UK guidelines needed in order to be accepted, even measuring them in front of me to make sure.
The location is a private residence in south Phoenix, but don't let that throw you off. He has a proper office and photography studio and all of the necessary means to take Visa/MasterCard and PayPal payments.
The prices were a bit more than CVS or Walgreens, but the photos will be perfect and the size will be perfect as well. And you'll likely get more photos for the money. I got 6. It took about 30 mins from beginning to end and I look forward to using Williams' services in the future for some family photos.
I would come back anytime I need passport photos or any photography needs.