People forget it's a Christmas Movie. The opening credits feature Jingle Bell Rock as that chick leaps to her death. After that it's another buddy cop movie. The granddaddy of cop buddy movies.
Crazy, suicidal Martin Riggs is teamed up with steady, retirement-ready Murtaugh to solve a suicide that turns out to be a murder that opens up a can of worms involving international drug-smuggling operation.
This baby spawned a buttload of sequels ehich is the whole purpose of buddy cop movies in the first place.