What are some of the scariest movie opening scenes you have seen?

That 28 Weeks Later segment starts midway through the openning, there's no proper context and build up. I'd recommend watching it properly from the start and in proper format with good audio/video quality if possible... The intro was shot by Danny Boyle himself so it's probably the best part of the movie, but it's still a decent movie overall.
Also, generally, watching cropped movie clips vertically (especially on a phone) in terrible quality and with those tiktok captions should be a crime imo 😅

One of memorable and scary opening scene for me is IT (2017) https://www.youtube.com/watch?v=zRL0Prr2oc8

The Ring, Texas Chainsaw Massacre (original, just felt unnerving to me), It Follows

I'm not much into horror movies, but for me Jaws is up there. 🦈

Thanks for the jigidi.

I personally don't find The Divide openning scary at all, shocking yes and definitely more likely to happen. But not scary in itself.

Ghost Ship is pretty good

Darkness Falls (2003) - Average move, but great opening
They (2002) - Just the opening
Ghost Ship has a great opening, but it's not scary in the slightest, just gore.