I last saw Hellraiser classic in 2016, so in general I'd say it holds up pretty well, even if S&M doesn't really feel like it should get you dragged into hell by kink demons in this modern age.
The Thing is definitely a horror. Scared the crap out of me as a mood too much not to be.
I've recently been revisiting the original Texas Chainsaw Massacre. True to its cultural impact, I really remember it having a lot more blood as a child, but there's maybe 4oz in the whole flick (not counting dried). Really worth your time still if you've never seen it before.