If you're talking about movies you wouldn't want to watch again...
The Sweet Hereafter is a fun-loving movie about a small Canadian town that has just had all of their children die in a horrific school bus accident. Here's a trailer for it, but the trailer is kind of awful.
http://www.youtube.com/watch?v=F7w-dPZI_LYThis is, without a doubt, the saddest movie I have ever seen. Ian Holm deserves special credit for acting in a role where the despair is bottomless. I really think this is a great movie, and I want to watch it again, but the incredible emotional investment I'd have to put in
again isn't something I look forward to.
If you're willing to watch a movie that will stick a knife in your soul and keep twisting, check it out. It is an amazing film. I don't have children. If I did, this movie would probably be too much.
It's a great movie, but...
I never saw that movie but the book is a real gutpunch. I probably couldn't take it.
Same with Cormac Mccarthy's THE ROAD
I haven't seen the movie, but I've read "The Road". And although it didn't live up to my expectations, it definitely struck a chord as I was expecting a son when I read it.
EDIT: Fixed repeating quote. -Mofo Rising