This Is England, not a perfect movie, but highly recomended.
It's a skinhead movie, and it does have its moments of extreme violence, but it also gives a great sense of how much fun they were having (even after the gang splits and the story follows the extreme Nationalist side). You'll laugh, you'll cry, you'll throw up a little in your mouth, and at the end of it all you'll have caught a very personal glimpse of a culture that usually only observed from the outside.
Probably deserves it's own thread, but it is late and I am lazy.