[JKfish]

Like Vilmarisv said, you'll probably get the best bettas right after they're shipped to your store. So, call and go the the store once they get their next shipment.

a healthy betta is active, and responsive. He will have his tail unclamped and flowy. He'll move around in his cup and have good colors.

A sick betta is either bloated or too skinny. He's unresponsive. He might have clouded eyes, rotty clamped fins, stress stripes, or pineconing. He will simply sit in his cup, with little to no wiggling or movement. His colors are probably faded and pale.