A good pilot is one who loves aviation so much, they will never do anything to damage its public image.
That means (to name just a few):
1. Recognising what you don't know about aviation;
2. Flying within the regs;
3. Operating your aircraft safely;
4. Respecting the needs and views of other pilots;
5. Respecting life and property on the ground; and
6. Caring about the "system" and contributing towards its improvement in terms of safety and efficiency.