This is tough for young people like me. There may be older movies like them that I'm not aware of.....But I would have to say:

RESERVOIR DOGS (1992) & PULP FICTION (1994)

At that time, I believe it was the late great Gene Siskel who said a lot of copycat hipster-ganster films will start coming out in the near future as a result of these two Quentin Tarantino films.

Siskel was right.