La Haine - French film from 1995 following three late teens/young adults in the aftermath of two teenagers' death. Perhaps it will be eye-opening for your classmates. It's urban, it's gritty, and it has an urgency to it in regards to racial and cultural tension. Classic.
The Class - Recent French film about a h.s. teacher and his students. I'd imagine they'd find most of it engrossing and relatable. Like La Haine, it could be eye-opening for your classmates.
High School - the great documentary by Frederick Wiseman. Takes place in a Philadelphia h.s. The time is the late 60s, but I think your classmates would find it refreshing to see that they can relate to it and that they're not alone which teens often forget.
Dazed and Confused - how familiar are today's h.s. folk with this Linklater classic?
Breakfast Club - how familiar are today's h.s. folk with John Hughes?
Take Care of My Cat - an overlooked Asian gem that could serve as a cautionary tale in ways in regards to post-h.s. graduation
American Graffiti - how familiar are today's h.s. folk with this classic?
Games of Love and Chance - Another French film. Like the aforementioned French films, it has immigrant/ethnic French teenage characters. A teenage boy joins a play in order to hopefully get with his crush. Slower paced than the aforementioned films and not as great, but an overlooked little film.
Linda Linda Linda - not in love with this Asian film as some are, but the scenes in which the band are playing music are fantastic