I'm divided on it. I think each decade had its bright spots. And as time passes, it's easy to look back and go "wow, that was the best era!" But they all had their waves. I'm a rock fan primarily so I tend to view the decades through that prism.
I miss the sunny vibe of the 80's. Bands like the Fixx, Police, Flock of Seagulls, Balaam and the Angel, The Cult, Pete Shelley, Peter Murphy, Julian Cope -- all this great alt rock. The album rock stations were loaded with great music -- Iron Maiden, Def Leppard, Ozzy, etc. Then you had the Oz music of the era: INXS, Midnight Oil, Rose Tattoo, Australian Crawl, Dragon, the Angels, AC/DC, etc For a while it seemed that continent could do no wrong.
I miss the 90's. Soundgarden, Pearl Jam, Korn, and a gazillion other bands of the era. There was an Oz band, the Screaming Jets -- they were awesome.
I also miss the turn of the century and the Nu Metal era. There was a lot of great music being produced from bands like Linkin Park, Saliva, POD, Skrape, StaticX, Disturbed, Slipknot and industrial bands like Apartment 26 and Filter. A lot of hard hitting rock.
Then things sort of went south. Rock radio began to disappear, and rock bands don't sell out big venues so much anymore, unless they're big classic acts like Metallica, the Stones and U2.
There was a small wave of good electronic pop music at the start of this decade... But overall, the 10's have been kind of a dull blur. There are a handful of alt bands that are OK, and two or three rock artists out there that are good -- Mastodon, Greta Van Fleet, PopEvil, etc., but not much really slams the radio speakers anymore. With everyone going to internet streaming for music, it seems to be less of a shared experience and more fragmented anymore.