I suppose the 1960s, but as I like to say about the many phases of my life, in terms of decade, age, location, activities, etc, "I thrive wherever I'm planted." So that I'm doing pretty well today and look forward to more good times, just different ones.
All my teen years were spent in the '60s, going from a boy of 11 to a young man of 20 by 1969, when I ended the decade in the US Army. So all the usual teen things marked the 1960s for me, like my first cars, first motorcycles, first sex, first drinks (legal at 18 then), becoming independent, earning money, leaving home.
Living through the terrible social & political turmoil we had, never participating in mass riots but getting caught up in a few and barely escaping. Watching our entire society nearly crumble, and change in ways difficult to comprehend today. And having my own personal disasters that left me seriously impaired for a time, and to some extent to this day. Not always happy times, but new, exciting, challenging & breathless ones.
But a close second would be the '70s: becoming an Army Officer, commanding a Company, returning to college to complete my degree, getting married, more cars & motorcycles I loved, the first of many cycle trips to lovely Florida, going to live in Germany, and ending that decade there.
The '80s were good, too: my Army career flourishing, now a field grade officer, teaching college ROTC, second marriage, first son born, lovely assignment in San Antonio, Texas, living in a gorgeous, big Army house near the Officers Club, camping in the Texas Hill Country in our RV, lots of field duty that kept me with the troops outdoors that I loved, having one new job after another thrown at me and mastering them all. At last I felt I really was a success at something.
The '90s and beyond were a mixed bag. My second son born, but my health declining, needing a cane & hearing aids. A rotten final assignment, though it did bring me to Seattle, where my marriage finally fell apart. Having to retire too soon, when I wasn't very far from General Officer rank. But the silver lining of realizing my gay orientation, and beginning a whole new life. That kinda blended into the 2000's, so I see both decades as one. Started having BFs, gained a partner, watched him die, found a new partner. Yeah, a mixed bag.
Now this decade -- what DO we call it? The '10s? New partner, going on 4 years, living in Paradise, more gay community involvement than ever before in my life. As I wrote above, good times but different ones. I wouldn't object if this decade eclipses the '60s, since its likely the last really active one I'll ever see.