Watchmen

I could ramble on about how good this comic is and how i'm looking forward to the film adaptation. But i wont!
Instead check out the official site for the film.
It's a great piece of flash animation and the use of images and sound from the film helps to create a very atmospheric site.

Watchmen Site

Also, for those that have read the comic, there are a couple of viral videos to be seen here on Youtube.