Stand By Me (1986)

This film follows four teenage friends; Gordie, Chris, Teddy, and Vern, is their quest to find a missing dead boy's body that they heard Vern's older brother talking about. The kids are under the house hiding when they overhear the older kids discussing the body and debating what to do about it, and whether they can make any money from turning it in.
The four boys go on the journey for curiosity's sake mainly. They set out on a long hike to search for the body, but they are really setting off on a life journey. They are all young and vulnerable, not only to the wrath of their older brothers who bully the kids a lot. In the film we learn that Gordie, the main character, had an older brother who was cool and really close with Gordie who passed away recently. Their father had always liked Gordie's older brother better, and he has really been coming down tough on Gordie since the passing.
The boys have a real adventure getting to the body. They follow traintracks to get there, battling nature, leeches, and high bridges to arrive at the body before their older brothers and their crew make it. Ace, Chris' older brother, is the tough guy, and seems as cold and heartless as they come.
After the kids make it to the dead body, in the "climax," nothing really happens at first, until the older kids come and an argument ensues. But when the kids see the body, they are all naturally sort of shocked. Seeing this makes the kids grow up quite a bit.
The thing that was strange to me was that these four who were best friends never hung around together after the trip. Gordy discloses at the very end that the kids eventually became just faces in the hallway.
This movie is an awesome story of friendship and I really enjoyed it.