There's a lot of things. For one, your dog has to like it, or else it's worthless if it's not being eaten. Two, I like for a food to be manufactured at the manufacturer's own plant, where they own the facility and actually make their own food there. Champion Pet Foods, who are the makers of Orijen and Acana, are made at their own facilities with their own quality control. Natura Pet Foods (Innova, EVO, etc) was/is? I don't know. They were recently bought out by Proctor & Gamble so I'm sure they're not anymore and I wouldn't feed any of their foods anymore. Fromm also has their own plant, as well as Nature's Variety (but I could be wrong on this one) and Petcurean Pet Foods (Go!/Now!). The only kibbles I'd probably feed currently are Acana, Orijen or Go! Endurance but that is because they do well with my dog, I like the companies, I like the ingredients, and I trust them. Oh, and I would feed NV Instinct again, Jackson did really really well on that food.
Some good websites:
Natural Pet Health - The Pet Health and Nutrition Center - your natural pet health store: Litchfield Connecticut New England Dog Food Analysis - Reviews of kibble Dog Food Reviews | Dog Food Ratings