Irreversible is tough to get through. But if you can make it, it's very rewarding. It is most infamous for its 9-minute, single shot, stationary camera rape scene. There is also a pretty gruesome scene where a guy gets bludgeoned to death in the face with a fire extinguisher.
By the way, are we allowed to share movies in this forum?
Enter The Void, from what I've heard, contains a somewhat graphic abortion scene, a violent car accident, gratuitous sex scenes and a shot depicting a penis entering a vagina from the inside.