Best how?
Each decade has it's good and bad points.
I was a kid in the 50's and 60's...so for me, the 60's were probably the best...but I can see why some think the 70's were pretty damned good too.
The 60's was the decade of EXCITING space exploration...OMFG! We started with monkeys...and by the end of the decade, we put a man on the moon!
Of course, there was that pesky Vietnam War...but that didn't affect TOO many kids...unless their father, brother, or other family member had to serve.
The 80's sucked...as did the 90's. Yes, computers, computer games, and video game consoles came into their own...but those are both good and bad...geeks lost touch with the outside world...and kids no longer play outside as much as they used to do...which is also good and bad.