What is a good life and the good life?

A good life is a life that is successful and pleasing to you according to your standards and viewpoints.

"The good life" was envisioned by Aristotle as the life one aspired to.

In the mid-20th century, the phrase became associated with the expensive, extravagant, and carefree lifestyle of the rich and famous. That it might be a hollow facade was expressed in the song "The Good Life", a standard first recorded in 1963 by Tony Bennett.