Hard to comment on the older decades.. didn't live through it but I'm sure the elderly will pick theirs. But for me, by far it was the 80's. You can look to music at the time to understand why.

80's - Music was 'fun', all music was, Rap, Rock, Metal people just wanted to have fun. Freedom, I was never home before dark and was outside all day long. No cell phones meant you didn't have somebody constantly nagging you, complete freedom to chose what you wanted to do as long as you got home by dark.

90's - Music - the decade of depression. Music turned into sadness with the Seattle scene. All the fun bands went away, bands like Metallica sold out and turned into some boring Rock band. You had Nirvana and all the 'Grunge Rock' come into play and kids just wanted to sit around and feel sorry for themselves. Odd time though considering the .com boom was going on. We saw our personal freedoms leave us with cell phones becoming more popular.. this is where helicotper parenting started.

20 - .com bust, kids thought the 90's was depressing but it was really for show, the 20's were really depressing with the market going to crap and people losing their homes. Music basically died with the internet coming into full power. Napsater vs Metallica etc. Music industry never really recovered. The age of the millennials was just getting started in school...

10's - Millennials.. end of thread.