Darkwalker

The Last House on the Left, The Evil Dead, A Nightmare On Elm Street and Bloody Murder 2: Closing Camp.

If we're literally looking for "biggest splatterfest", then my vote would go to Braindead / Dead Alive: so ridiculously over the top as to be hilarious.

For notorious, graphic or grisly death scenes, either the fire extinguisher in Irriversible or the "cheese cutter" device in Cube: the first casualty.

They Dont Cut The Grass Anymore is pretty gory, but they use sex dolls as bodies so not very realistic!

So I agree that Braindead (Dead Alive) is probably the goriest.