NOT Blue Buffalo or Pedigree; both are known to cause dogs serious health problems.
I haven't heard of any bad outcomes from feeding ProPlan or Fromm.
Edit: What I would like to know is whether certain ingredients, such as grains or carbohydrates in general, seem to lead to greater risk of cancer.
Since the National Research Panel Council has found that dogs don't actually need carbohydrates, I am suspicious of high-carbohydrate foods, especially those containing a lot of grain, and I am feeding the lowest carb food I can find, Orijen.
Added:
What's wrong with Blue: there are too many reports of dogs who developed problems while eating Blue.
The only problem Orijen causes is runny stool at first, which can be fixed by adding a source of fiber such as pumpkin or beans. And now, after 3 months of eating Orijen Large Breed Puppy, my puppy has adapted and no longer needs the extra fiber.