Also, the question was about albums that define the 1980s. I didn’t see a requirement that they had to be released in the calendar 1980s.
Yeah, “London Calling” was an album that certainly foreshadowed much of what happened in the 80s (and further into the 90s), especially the effortlessly blending of that many different musical styles and genres.
Don’t know the answer to your question, but yes, The Pet Shop Boys produced perfect pop music throughout most of the decade (and beyond), and you could pick from a number of albums, at least for the UK. The Smiths cover more or less the same period (though less obviously pop) and again you could choose from a number of albums.
j