I don't rotate on a schedule, it's all pretty random (perks of working at a pet food store!). I'll feed any of the proteins/formulas, but we do try to stick with the grain-free varieties.
Orijen/Acana, Fromm, California Natural/Innova/EVO, Holistic Select, Canine Caviar, Nature's Logic, Precise, Earthborn Holistic, Lotus, NutriSource/PureVita/Natural Planet, Go/Now, and Nutrisca.
There are definitely other brands that I would feel comfortable feeding, but these are the ones that I can get through work, so...yeah.
I'm feeding Now Adult currently. In the "dog food cupboard", I have NutriSource Heartland Select, Nature's Logic Sardine, Lotus Duck, Canine Caviar Herring, Orijen 6 Fish, and Earthborn Meadow Feast, so we'll be rotating through those.