There are a whole slew of more "underground" gore films out there - in fact, despite being a niche market, it's still a rather large market as a whole. There are entire conventions catering to this stuff. The "August Underground" series would be part of this group, but there are many others as well such as the "Guinea Pig" films, and the "Nekromantik" films too. One of the newest ones I had watched is called "A F*cking Cruel Nightmare", which is literally just some guy walking through a house draped in plastic sheets, watching these strange masked figures torture and murder people - while death metal music is playing throughout the whole movie. The whole movie was just kind of punk and silly, it was amusing if you are in the mood for something mindless and off the wall. There was another series of films from the early 90's called "Violent Sh*t" that spawned several sequels. It was just some guy in armor walking around and mauling people, with some German heavy metal band singing some theme song they made for the movie - the song is actually quite catchy if you like metal, lol. Another one from around 2006, I believe, was called "Header" and was about this deranged family that local criminals would bring their victims to for a "header". The "header" was basically an act the goofy grandpa and his grandson would carry out on the victim. The grandpa would drill a hole in the persons head, and his grandson would literally f*ck it. "Chaos" was a (2005/2006?) ripoff of the far more famous "Last House On The Left", which itself was a remake of a far more tame classic film called "The Virgin Spring". Roger Ebert for some reason reviewed the movie and totally trashed it as one of the worst movies he had ever seen. The other reviews of it are also pretty scathing, and rightly so. It's just a mean spirited film across the board, with nothing interesting or intriguing about it.
Definitely the Serbian Film stick out to me. Lots of scenes from this movie can really make you throw up, good thing, I was able to restrain myself from being a mess. This movie has graphic depictions of rape and necrophilia. I just can't stand these types of genre, so for me, it's the most gross film in existence.
I don't think you can put Violent shit in with faux-snuff stuff like August Underground and Guinea Pig, though.. Violent Shit isn't even that bad, really. I mean, it's probably not even trying to be bad, at least that's the vibe it gives to me.