Flatliners

Flatliners is a 1990 movie starring Kiefer Sutherland, Julia Roberts, Kevin Bacon, William Baldwin and Oliver Platt as medical students experimenting with near-death experiences. In the course of their experiments, they accidentally bring back the ghosts of their past, in the form of vengeful entities that torment them, forcing them to confront their past mistakes and try to figure out a way to send them back where they belong.

A pseudo-sequel was made in 2017, and the less said about it, the better.

Tropes used in Flatliners include:

Blond Guys Are Evil: Nelson and David when they were younger
Casanova: Joe
Cassette Craze: Randy Steckle is constantly talking into his tape recorder, taking verbal note on the experiments and such.
Casual Danger Dialogue: When the guys are rushing to stop Nelson from trying to commit suicide Steckle remarks how his worst sin was robbing a sandwich from his babysitter.
Crossing the Burnt Bridge: The entire movie is about this.
Dead All Along: Billy Mahoney
Deadpan Snarker: Steckle.
Flatline: To nobody's complete surprise, this happens a lot.
Flatline Plotline: ...yeah. The best-known, if not the first, such example.
How Dare You Die on Me!: While David Labraccio (Kevin Bacon) is trying to resuscitate Nelson (Kiefer Sutherland) at the end of the movie.
Ho Yay: Virtually every scene where Nelson and Dave interact.
If You Die, I Call Your Stuff: He says he was joking.
Magical Defibrillator: In Real Life, it is not possible to defibrillate someone who is flatlined back to life, let alone someone who has been clinically dead for twelve minutes. We won't talk about brain damage, either.
Meganekko: Rachel.
Mirror Scare: Rachel (Julia Roberts) looks in a mirror and sees the ghost of her dead father on the room behind her.
Nipple-and-Dimed: Averted, surprisingly. The Abyss did this with Mary Elizabeth Mastrantonio, and it was PG-13. Flatliners is already rated R, and even has a sex scene in it! But Julia Roberts has a bra on during her resuscitation scene.
Positive Discrimination: While all the men in the group have to deal with the various people they hurt in their lives, the one female in the group's only sin is having a father who committed suicide when she was a child, through no fault of her own.
- Though in the original script, her sin was an affair with a college professor where she villainized him after being caught and claimed sexual abuse. The storyline was changed so as not to reflect badly on the reputation of "nice girl" actress Julia Roberts.
Professor Guinea Pig
Romance on the Set: Keifer Sutherland and Julia Roberts.
Ship Tease: Rachel and Nelson.
Suicide Is Painless
Trashcan Bonfire: Steckle and Hurley warm their hands over a burning barrel before being picked up by David Labraccio.