I'm going with the Paul Newman's organic dry cat food. No wheat, no "meat by-products" (meaning diseased or dead chickens, among other sordid ingredients of "meat by-products" which are not allowed in human food), and one would hope no pesticides because it's organic chicken and organic vegetables.
It's expensive- locally $10 for a 3.25 lb bag.(!) But that lasts a couple weeks for our 3 cats. Our cats seem to love it, and they are pretty picky.