If you're after one of the most depressing movies of all time, look no further than 12 years, a truly descriptive means of illustrating the torture and conditions faced by African American slaves within the late 19th century.
I'd say it's definitely up for a few Oscars, just by the cinematography and the beautiful ways it captures the dark and horrifying conditions the slaves were kept in.
I would say this is the best movie I have seen so far from last year and it would be no surprise that you too would be shaken, moved and left disgusted on how people were treated to their inferior ways. A must watch.