To Live and Die in L.A. (1985)

Definitive film of that decade. Friedkin’s masterpiece.

Otherwise, Blade Runner is a must. Final Cut is easiest, but revisionist in certain ways. Best of all the is the 1992 director’s cut but it misses the bits of violence from the International version.

As mentioned by others and other random 80’s releases that spring to mind:
Road Warrior, Planes Trains and Automobiles, Empire of the Sun, 52 Pick Up, The Killer, A Better Tomorrow, Police Story I and II, Full Metal Jacket, Midnight Run, Prince of the City, Once Upon a Time in America, After Hours and other Scorsese entries…and many many more.

I always defend the 80’s Bond era under John Glen, as there’s always something of interest onscreen, but if you have never seen the Dalton entries do so immediately.