A lot of movies that scared me when I was a kid just kinda make me laugh now. But two movies still hold up and give me that sense of ewww, especially if I watch them at night. Phantasm and Burnt Offerings.
Oddly I watched the two pretty close together earlier this year and realized (altho a bunch of real horror fans already know this) that the Burnt Offerings mansion and the Phantasm Mausoleum are the same place in real life. It's called the Dunsmuir House:
An otherwise lovely old normal house, now tainted with horror.
The house gives off a completely different vibe of evil and dread in each movie. In Burnt Offerings it's a beautiful mansion that's gone neglected, and initially seems like a great family home. In Phantasm it's a freaking creepy mausoleum you see off in the distance at night and don't want to go anywhere near.
Both movies have a creepy tall man. In Phantasm it's the man who runs the mausoleum, and he's actually referred to as the Tall Man. And in Burnt Offerings it's the scary chauffeur with the toothy evil smile.
Wrong kind of smile. Wrong kind of ball.
Probably the reason they are both so harsh for a kid to watch is that in Burnt Offerings the parents go bad (via the house), and the boy in Phantasm has no parents. There's no one to protect the kid in either movie. But at least the Phantasm kid has a cool older brother looking out for him, and the Burnt Offerings boy has his aunt (Bette Davis). Too bad Bette Davis gets dragged away to be buried alive, and the Phantasm kid ends up in all kinds of horrifying danger despite his brother's concern.
Both movies are just like nightmares. Burnt Offerings is a subtle nightmare until all hell breaks loose at the end. Phantasm is a full-on mega nightmare.
Burnt Offerings probably messed me up worse because I was younger when I saw it, but Phantasm wins all around for one creepy image after another. People smashed down into creepy Jawa critters, the finger in the box, the silver ball that drills a hole in your head, the traveling to another dimension via two poles in the mausoleum...