I had nothing social to do this weekend so I watched a bunch of movies. If you are a fan at all of film noir, you must go out and rent Brick. Now, if you don't know what film noir is, here is a pretty good (and long) description on wikipedia, with many examples. Basically, if you think of old Hollywood movies about sketchy private eyes and tough, manipulative dames all in a dark and gloomy atmosphere, that is film noir. It is a broad term though, and there are many variations, especially in Brick.
This movie takes place in a modern day Southern California high school and all the main characters are students, or of that age group, yet they all talk in a 50s tongue and they act the parts, too. This is what I love about film, you can create a world that is completely absurd, but it can work to make a fabulous film as long as it stays consistent to the rules of that world. That is exactly what this movie does. At first you are a little taken aback, but the movie stays consistent in the characters it creates and the world in that it lives and you get sucked in. So, my suggestion to you, if you have about 4 hours to kill, go out and rent a classic film noir (I highly recommend The Maltese Falcon) as well as Brick and then watch them back to back. It will give you a great appreciation for the skill in which the latter was made, and how perfectly it captured the spirit of those great films that preceded it.