The 50s was the infancy.

The 60s was the where it really all happened.

The 70s was the refinement and offshoot era.

By 1980, it began to repeat itself. The copy is very rarely as good as the original.

So it's a toss up between the 60s and 70s. Personally, I like 1965 to 1975 because it was the convergence of technology with an open minded youth culture.

But I think a lot of it has to do with when you grew up. I picked the 70s.