For me, it depends whether I can care about the characters I'm watching, and whether what's happening is an important part of the story they're telling. If so, then fine. So no problems at all with Night of the Living Dead, or Event Horizon, or Aliens, or 28 Days Later. Or on a less horror note, Con Air or Die Hard.
But Goodfellas was kind of pushing it for me, because frankly I wanted the lot of them shot for the good of the world as a whole - I don't see the point in making films celebrating scum. Seven, I couldn't stand another minute of Brad Pitt failing to act. GI Jane, the end scene of gratuitously invading a foreign country and shooting their people (whilst presenting this as a victory) left me sickened. Aliens 3 and 4 were just an excuse for having people eaten by rubber-suit creatures. For non-horror ones, having just seen the Johnny Depp/Tim Burton version of Charlie and the Chocolate Factory, I could happily drop the Great Glass Elevator and its cargo of monsters into the nearest Voracious Knid. And I'm entirely with Wesley about the battle-of-the-sexes crap.
I don't mind films which I can't watch again. Event Horizon is one such. I found it great, but it was so disturbing that I couldn't face it twice. Still, I'm very glad I saw it. I've not seen NBK, but I guess it might fall into the same category. Taxi Driver certainly did, as did Apocalypse Now.
Re your line: "That crap can't be good for kids and some adults to see". It certainly isn't good for kids to see, which is why there's film certification and rules about how old kids have to be to see stuff. But the point of being an adult is that you're supposed to be able to make decisions about whether you want to watch this stuff or not.
And FWIW, I quit my reading of the Iliad after multiple pages of "X kills Y like this" and handing slave girls round as commodities. Plus ca change...