Conceived as an angry reaction against the dominant John Hughes high school comedy model of the time, 1988's Heathers is also a wonderfully macabre twist on the romantic comedy, which still hasn't lost its sting 30 years later (and hopefully still won't once the doomed-to-disappoint TV reboot airs later this year).
Winona Ryder (in her first leading role after breaking big in Beetlejuice) is Veronica, a popular girl thanks to her association with elite clique the Heathers, so-called because all of them aside from Veronica have that same first name. However, Veronica is quickly losing patience with their back-stabbing, superficial ways.
Enter Christian Slater as JD, the enigmatic new kid at school, and a walking bad boy cliche with his long black coat and motorcycle. Bewitched, Veronica happily gets swept up in a whirlwind romance with this exciting stranger - but finds out too late that he's completely psychotic, and is manipulating her into helping him murder the bullies that rule their school.
Heathers has always been most noted as a biting satire on life as a high school student, frequently cited as an influence on any teen comedy that takes a similarly satirical approach (e.g. Drop Dead Gorgeous, Mean Girls).
However, it's also a dark antidote to your standard movie romance, questioning the validity of 'love at first sight,' and demonstrating how easy it is to lose sight of oneself and one's better judgement when caught up in the fog of infatuation.