Hmmmm. Good question. My first response would be the 40s because I love the fashions and music of the "big band" era.
However, I love the mid 1800s, too, with all the excitement, Civil War, etc. Not that I consider the Civil War a warm and fuzzy thing. I think it has more to do with changes and advancements.
I love the evolution of customs, dance, fashion, foods, etc. that happen over time. Poodle skirts, hula hoops, fondue, those sorts of things. Every era is filled with all sorts of fun. Even those that had leisure suits and afro hairdos. Everything has its place.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!