I've gotta go w/ the 60s. You've got:
British Invasion (Beatles, Stones, Animals, etc)
Classic Rock American Bands: Hendrix, Doors, CCR, Velvet Underground
Motown: Stevie Wonder, Marvin Gaye, Smokey, Temptations, Four Tops, Supremes, etc
Stax Records: Booker T, Rufus Thomas, Otis Redding, Eddie Floyd, etc
Plus the Phil Spector Wall of Sound.
Every genre churned out some great music. . . . . Even standards like Frank Sinatra churned out some great records that decade w/ his Reprise label.
Every decade definitely has lots of good in it, but for me the 60s is the deepest.