For comparison, the top-rated English language feature films of 1987 on IMBD are:
Full Metal Jacket (8.3)
The Princess Bride (8.2)
The Untouchables (8.0)
Evil Dead II (7.9)
The Last Emperor (7.9)
Matewan (7.8)
Withnail & I (7.8)
Empire of the Sun (7.7)
Predator (7.7)
Lethal Weapon (7.6)
The Year My Voice Broke (7.6)
Maurice (7.5)
Planes, Trains & Automobiles (7.5)
Raising Arizona (7.5)
RoboCop (7.5)
Hope and Glory scores a 7.4, Broadcast News and Moonstruck both score a 7.0 (too low for Broadcast News in my view), and Fatal Attraction scores a 6.8.
It was a very strong year for films, but the Academy got the nominations and the winner wrong in my opinion. Moonstruck and Fatal Attraction are both good films, but they should never have been nominated ahead of Full Metal Jacket, The Untouchables, and Empire of the Sun. In fact, either Full Metal Jacket or The Untouchables should have been the winner that year.
It's been a long time since I've seen The Last Emperor and I need to see it again to refresh my memory and reevaluate it (I recall finding it a well-made film that was overlong and a bit dull at the time), but out of the nominated films I'll throw my vote to Broadcast News, a film I've always had a soft spot for (although, again, it wouldn't be my choice as best of the year if one includes the above-mentioned omitted films).