For a reasonably priced, off the shelf bag found most anywhere, it is hard to do better than Purina's Flock Raiser for an all around chicken feed. I will join
@aart in that recommend, though I don't use it myself anymore.
Nutrena's Nature Wise All Flock is nearly as good, if slightly more expensive (usually) - a couple pennies a pound. It carries the "All Natural" label, which most certainly is NOT "Organic".
If you are shopping a TSC, DuMor has two vaguely "All Flock" type feeds, a 17% protein you should avoid, and a 20% protein which is remarkably good at the price point - but check the mill date very closely. There are a number of threads on BYC about bags of DuMor very old (I blame TSC's inventory control and store to store shipping practices) or reduced to powder (ditto).