The first film is the closest to an actual story, basically it's your standard revenge flick, with the most well-rounded characters found in the trilogy, and it actually manages to evoke some sympathy and maybe understanding from the viewer.

The second is the most violent and unrelenting of the three, and possibly my favorite. Not, necessarily because it is so violent and cruel, but simply because it had the power to unsettle me.

The third film is the most disgusting of the three and is the one most likely to exercise your gag reflex. Not necessarily violent, just perhaps more of an intimate look at the human body and it's functions than I would have liked.

Although all of these films are virtually plotless (with the exception of the first), I must give them credit for the fact that each of them managed to evoke such a strong physical and/or emotional reaction from me. These films aren't exactly what one would call "entertaining", but the fact that they can affect the viewer in such a tremendous way has to be worth something.