I would say the greatest times would have been the 1940s with the exception of WWII. If Hitler never happened the 1940s would have been the spotlight years in America.
I say this because even though we were still experiencing some of the affects of the Depression that's when jobs as we know them today came about. Before you didn't know if you were going to work 20 hours a week or 60, you can be working at one company for a week and then go to another one the next. The jobs weren't consistent. There was even an extreme case (I know it's true because my grandfather's dad experienced it) of mining companies in West Virginia advertising for great jobs with great benefits but when people got to the town, it was really a "prison camp" with the company using people as a form of slave labor. My great grandfather learned of a way to escape and he fled to Detroit, Michigan.
I have never dug deep into what life was like for the average Joe but with what I do know I feel that the 1940s (with the exception of World War II) were America's Golden Years.