I always prefered Need You Tonight, but it's probably too upbeat for this list.

As for what you left out, Pet Shop Boys may have a reputation for bangers, but they also have some amazing slower/more mid-tempo tracks.

From the 80s:

West End Girls (possibly too uptempo), Love Comes Quickly, Violence, King's Cross, Do I Have To?

From the 90s:

Being Boring, This Must Be the Place I Waited Years to Leave, Jealousy, Liberation, Decadence, You Only Tell Me You Love Me When You're Drunk, The Ghost of Myself

From the 00s:

London, Vulnerable, The Way It Used To Be

From the 10s:

Leaving, Burning the Heather

Some of those are achingly sad, but so beautiful.