Generally speaking, the music of the past decade has been about splicing together disparate styles of music to create new genres. It was the decade that the internet allowed anyone a chance at musical stardom. The invention of mash-ups allowed people to experience their favorite types of music while being exposed to something they would not have otherwise thought to listen to. The nineties and the decades before that consisted of new mutations of older genres (i.e. punk to grunge), but never in this capacity. The Billboard Number 1's did not sell as well because everybody was listening to something different.
I'm sure there are many people who disagree about the decades in terms of which is better, but I think ultimately that period in our live where music is new to us and we are going to lots of concerts and overall spending more time and money to consume music is the point in time that we label as the "golden age."