Personally I think Conjuring is the best one on this list and is a perfect example of a “modern horror classic”. I also do feel like Sinister will be regarded as a classic. Maybe not as high but will still be talked about. And personally I do also feel like Paranormal Activity will also stick around. I’m 23 so I was really young when it came out but I remember when the promotions and commercials came out and how the whole “is it real convo came to be”. I think with it to keep it alive you almost have to show the next generation of horror fans when they’re at the right age where they’re young enough to believe it but old enough to not be scarred.
Also I will have to disagree on the scream take. I think it’s almost like a package deal with them and you get to play a game with it. The first one is 100% the best and is what gets you hooked but me and my sisters binged the others and played who the killer on each of them and because of that gimmick I think they will also be remembered.