a-Ha's Take on Me could be one of the top, though that was driven in part by the video. But Hackett hits a note that I'm pretty certain isn't actually on the music scale. That note is the musical equivalent of infinity.
I think Michael Jackson's Thriller or Billie Jean needs to be given considerable consideration.
And about half of The Police's Synchronicity album, Synchronicity II, Every Breath You Take, On My God, Wrapped Around Your Finger, Tea in the Sahara. While the last one wasn't a radio hit, I think it is the best song on the album that was so good, it broke up the band.
Don't You, by Simple Minds. I'd consider that a time capsule staple for the 80s.
These are all good. I was a huge Police fan, and am now rediscovering some of the songs which got little to no airplay. This is why I'm not a fan of the more recent trend of buying single songs. I mean, if you
know you only want/like the one song by a band, then fine. But otherwise, I've found often my favorite songs on many albums are ones which never got any airplay (outside of perhaps some small college stations). Also, pretty much anything from U2 in this era was good, too.