The 1950s. It was really lame stuff. Presley was about it. That's what let the Beatles, Stones, Zep, and the Who take over with fury in the 60s. it was pretty easy to be better than the crap the kids listened to in the 50s.
I think the 80s were the weirdest decade of my lifetime. You had total pop #1s from Debbie Gibson, Cindy Lauper, Huey Lewis, Madonna, Hall and Oates, etc. But at the same time there were #1 hits from a lot of metal/hair metal bands of which some bands were actually talented but everyone seems to have their own opinions on (Cinderella, Tesla, Crue, Whitesnake, Queensryche, Def Leppard, Poison, Warrant, Ratt, Hanoi Rocks, etc). While at the same time Prince and Van Halen were pretty awesome throughout the entire decade.