Heathers (1988)
The 1980s was featured a whole catalogue of angst-filled teen comedies and dramas. Heathers took this genre and flipped it upside-down. Instead of the never-ending adolescent battle to find their place, or to fit in, this film basically says, "don't just wish death on your rivals, go ahead and do it instead."
Heathers features Winona Ryder and Christian Slater in two of their earliest roles, although, for many cinema goers, they'd already seen Winona Ryder in Beetlejuice
Hmmm, what else to write?