KFC is the worst fast food chicken, just a weak choice all around.
Popeye's spicy is my #1.
Chinese food spot chicken is #2. The key is to look for the one with the oldest, thickest bulletproof glass.
3rd are the cheap chicken spots named after Presidents, or have some variation of "Mama's" or "Crown" in the name. These are catch-all fast food places on the east coast, I don't think they have them on the west coast. They usually are hit or miss on the spices, but when it's good, it's good.