I used to love champion but I've got a bad taste in my mouth over the years. Their formulas look fantastic on paper but they don't seem to work for every dog. Its a very rich food. If I were to choose I would go with Acana and perhaps even their limited ingredient lines. That being said I do use them for treats for my dogs.
These are my personal go to Brands:
Fromm (works for many dogs, though I am not in love with the ingredients)
I have only personally tried a few of these but I've only heard good things about most of them.
I personally have a big thing about quality control and ingredient location. Therefore Diamond is out, too many recalls, even if they were just for Salmonella. Same with the recent EVO recalls, though I was never comfortable with the ash levels in EVO. I believe Nature's Variety Instinct sources their rabbit from China, so that taints the brand name for me.