Cannibal Holocaust Reviews
The only thing I found inexcusable was the animal cruelty (save when it was clear the tribes involved in filming were using the animals for food).
Apart from that, Cannibal Holocaust is grisly, gritty, and disgusting. Its makeup and effects are impressive. And for a found-footage film - arguably the first - its cinematography is surprisingly competent. It's a film worth watching for those interested in exploitation and/or horror - anyone else should stay very far away.