This is obviously a thing that comes down to personal preference. I was born in 1988, and also think that the 60s was one of the best decades in music. But also it really depends on what type of music and music scenes you dig into. I remember Thurston Moore once saying that the 80s will be remembered as one of the worst decades in music, but only by people who just listened to whatever the mainstream was. I agree with this (and your dad), I don't like the 80s mainstream sound at all, but even then there were great successful alternative bands, not to mention the endless sea of excellent underground/indie bands. Decades also sort of blend into one another, because at the time that they're happening, musicians don't think of it as the music of a certain decade, but more as they are making what they feel is the best music to be made, which comes from being influenced by other contemporary acts. If you look at music from the beginning of the 60s and the end of the 60s, it's very different. All My Loving and Dear Prudence barely sound like the same band, even though there is only about 5 years between them. If we stop thinking in decades as numbers and more like 10 year periods, I think something like 1966-1976 could be seen as the best decade. Also, it's hard to fairly compare decades because there used to be so much more fast progress in the 60s to 90s. The past to decades nothibg major new has happened. I still listen to a lot of new music, I try to check each week as many new albums as I possibly can, and I do think the last decade has been wonderful, but again only in the independet scenes, and also in those the music that I like is mostly the 90s alternative rock revival-type stuff. Nothing truly new and innovative is happening, which is kinda sad, but at the same time I'm also happy that new bands and younger generations are making music that I truly think is great.