Favorite underappreciated movies

There are a lot of great movies out there that people do not know about,
One of my favorite movies in particular is:
The Specials.
I love this movie, its about heroes, they arnt using their powers and such, but this movie is about them in their normal lives. I think this movie is really good because of the style that they show the heroes as. They are just as weak socially as any other human.I just love under appreciated movies like these and I want to see more, is there any other movies I have not heard of but I should watch?

What do you mean by unappreciated? Do you mean unpopular, or old, or what?

Six String Samurai

Joe Dirt
Napoleon Dynamite