The Last House On The Left (1972)

An instant classic, the first film ever to depict a chainsaw as a weapon, graphic lesbian rape, murder and mayhem. Fun for the whole damn family.

I have been lucky enough to watch the full uncut version (With what is left of the scenes thought to have been lost fovered, left in). The film has been bombarded with so many different censorship restrictions across the world that many scenes are cut on most versions of the film. In fact most versions of the films labeled uncut have scenes cut from them.

The missing or rare scenes are:
Lesbian rape scene - One scene long-thought lost, except as a photographic still, is the two female victims forced to commit sexual acts on each other in the woods. This forced lesbian rape scene was found as an outtake with no sound to it on the Metrodome Three-Disc DVD Ultimate Edition as well as the 2011 Blu-ray release.
Mari in her room - Photographic stills exists showing a nude Mari in her room in the beginning of the movie where she is reading birthday cards, the shot scenes of this no longer exist.
Mari raped by Sadie - Short cuts showing Sadie committing sexual acts against Mari in the woods is often cut out, even from some DVDs that have been labeled as "uncut".

As a long lived classic, I recommend watching it.

Another one very high up on my to-watch list.

Of course I'd only watch the completely uncut version.

The completely uncut version is only uncut to a certain point. Some scenes are only available as stills in the bonus features, as well as a scene which was only available in silence. It is rumored that in a new special addition of the film, they have been digitally recreating the audio for the silent scene using people sound-alike voices and filling in the background music from the existing soundtrack. This has not happened yet and it was never confirmed that they have any plan to do so. It would be pretty cool though.