I would like to specify five under appreciated heroes because the traditional ones have been mentioned by other Quorans.
1- Dutch Schaefer (Arnold Schwarzenegger) in Predator (1987).
Dutch’s muscles are no match for the Yautja’s plasma cannon and arm blades. In the end he survives by using humanity’s greatest weapon: ingenuity. Hence proving that humans are the apex predators on Earth.
2- Jay Height (Maika Monroe) in It Follows (2014).
She is an innocent girl thrust in a deadly predicament by her douchebag boyfriend. Jay’s friends are her greatest strength. Everybody sticks together in this horror film.
3- Jess Bradford (Olivia Hussey) in Black Christmas (1974).
One of the earliest examples of a ‘final girl’ in a horror movie. She’s kind to others and even vulnerable at times but Jess stays brave in adversity.
4- Chris Washington (Daniel Kaluuya) in Get Out (2017).
He notices something is off about the Armitage family from the get-go. He ignores their awkwardness at first but is quick to trust his guts.
5- Almost everybody in Tremors (1990).
Bet you didn’t see that coming. Val (Kevin Bacon) and Earl (Fred Ward) know how to ride horses, fire guns and are smart enough to assess the Graboids’ intelligence. Earl gives the ‘fishing’ idea to hunt the Graboids.
Burt (Michael Gross) and Heather (Reba McEntire) are firearm experts and have an arsenal that the townsfolk use to fend off the giant worms.
Rhonda (Finn Carter) is a seismologist and is able to determine that they’re dealing with prehistoric organisms that hunt by detecting sound. She comes up with the idea of pole vaulting.
The remaining supporting characters are either part of the movie’s body count or are there to raise the stakes for survival. Even those who end up dying didn’t make stupid decisions but were victims of bad luck.