The monster that ignited a genre. (Terminator and Die Hard were years away.) Sylvester Stallone in a sequel-prone vehicle, at a time when vets were portrayed as walking PTSD bombs after a long questionable war, and the cops were seen as running roughshod over civil liberties with a casual indifference, because they could.
In other words, a 1982 film ripped from the headlines of 2014.
Brian Dennehy and Richard Crenna balance out the testosterone-laced love triangle in this movie, and it's doubtful anyone other than Stallone could have pulled off the lead in this movie, then, anytime since, or ever.
You also have to watch it to notice, but Stallone goes through most of the movie, whole yards of scenery and action, acting while uttering fewer words of dialogue than Marcel Marceau. And pulls it off with an epic verbal meltdown at the end. He mops up the floor when it's Rambo v. cops, then kicks ass when it's Rambo v. Nature, and it's only when he finally has to fight himself that he loses it at both ends.