Lets pretend this thread is only discussing the modern era of music from around 1950 on with the establishment of the relatively standard album format, which we might loosely call "popular music." While this is a gross disservice to the massive variety of absolutely amazing music that came before it, lets try it for the sake of discussion. With that constraint, you still have:
50s:Jazz, (Electric) Blues, Rock and Roll
60s:Rock (Pop, Blues, and other variants), Avant Garde/Experimental Rock, Psych, Free Jazz
70s
rog, Funk, Hard Rock, Psych, Reggae
80s:Metal, Punk, Electronic, Pop
90s:Extreme Metal, Mainstream Rap, Post-Rock, Indie, Electronica
00s:Underground Rap, Experimental Pop,
To say any of those decades is lacking in quality music is to be incredibly closed minded and grossly ignorant, and this is about the most horribly boiled down and insulting breakdown I could come up with. Every one of these genres only peaks where I placed it, but they usually started a decade or more before, and none of them actually ever stopped being produced. The only thing I can possibly hold against the 00s is that less genres found their way in the decade, but that is easily overlooked because of the volume of genres that quality music is being produced in.
In short: If you don't actually like music, stop talking about it, and if you do like it, then try expanding your horizons.
(drkirby stop acting like you listen to music.)