Salo has no gore in it really, just a lot of torture and sexual depravity.
Nekromantik has some gore in it (the decapitation), but the main focus is on the sexual relationship between the main character, his girlfriend and the corpse he has stolen.
Aftermath is quite gory, but that's to be expected in a film about an autopsy, and what the morgue surgeons get up to with the lifeless bodies.
Last House on Dead End Street is a mixed bag. There is a fair amount of gore in it which helped to gain it the reputation it has - most of the gore stands up to todays standards - plus it is a grainy film which adds to the realism, but it's also the twisted characters which help to make it a disturbing film.
Ebola Syndrome has a decent amount of gore in it too. There is also a lot of black humour in it though.
None of these films are played for laughs though, and the gore is relevant to the experience, and not just thrown in for cheap shocks.
Some other films you might want to check out if you like sick and disturbing cinema are...
August Underground
Visitor Q
Red Room 1&2
Seketsu No KizunaBeware though, there is some disturbing shit going on in these films, so bear that in mind if you decide to check them out. I've known a fair few people who think they've seen it all cause they can handle stuff like The Evil Dead, Braindead and The Texas Chainsaw Massacre, but upon seeing some of these films, lose their lunch pretty quick.
I get lots of ominous looks nowadays when I suggest that I bring a film round on a saturday night

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Every dead body that is not exterminated, becomes one of them. It gets up and kills! The people it kills, get up and kill!! - Dr Foster, Dawn of the Dead.