Apocalypto
Why did my parents think it was ok for me to watch this as a child? I'm not sure either.
This is definitely the most memorable movie from my childhood though and rewatching it reminds me why this movie stuck with me. I'm surprised this movie doesn't fall under horror with how unsettling, gory, and traumatizing it is to watch. Nonetheless this movie is fucking great and always will be, maybe I'll make my future kids watch it.