Okay, so this probably isn't the most delightful entry on this list but it is the most authentic.
The harrowing pub scenes in
Nil By Mouth
were drawn from very real experiences.
According to director Gary Oldman. "There is a lot of me in there. I grew up in that neighborhood. All the locations are the actual locations I remember. My mother used to sing in that pub. The bar where you see the father sitting alone—that's where alcoholism puts you. Drinking whiskey chasers at 9:30 in the morning on your own in a pub. It's really attractive, you know? Great life. That pub is the pub my father used to go to, and where he destroyed his liver."
So, yeah, not exactly cheery - but essential viewing all the same.