imo
requiem for a dream.
3 groups of people,
start working toward something they want,
and with solid goals,
fall short of the finish line,
and fall fucking hard.
Although unrealistically, they inject heroin and their pupils dilate, the movie really draws out on some realistic emotions and possibilities.
The plot, is so fucking easy to relate to, from any drug user, or anyone who's ever tried to achieve more than they're getting in their lives.
And really follows the very real fear of addiction, in any persons mind. Not even just the addiction to a chemical, the addiction to a want, a desire.
I haven't seen any drug-related movie like it, but i'd surely like to, or even one better :d

your favorite?
Good watches?
Etc.?