Our natural fear of the unknown immediately makes us keen on blending Science Fiction with Horror, but the combination isnāt all that easy to pull off. For every Alien, you get ten movies like The Happening, and, well, the Alien sequels.
Here are ten movies that did the formula justice, some of which even pushed the genre forward by adding surprisingly effective, fresh new elements.

Cloverfield (Matt Reeves, 2008)
Movies about big monsters ravaging through a city rarely fail to entertain, no other did it better than Cloverfield, the only film courageous enough to ask people to experience all the fear and devastation in first person perspective.
The found footage genre can go from scarily horrifying to incredibly good at putting you to sleep. After The Blair Witch Project, Cloverfield is likely the most interesting attempt at this genre ā and one of the best Kaiju films ever made.

The Mist (Frank Darabont, 2008)
If you want to see a truly messed-up alternative to the father-and-child dynamic of The Last Of Us and Logan, you can do no better than The Mist. Instead of a bunch of people who get more than they bargained for by venturing where they shouldnāt, The Mist tells the story of a family just going about their business when their town gets engulfed by a mysterious mist that, you guessed it, is hiding scary things within.
Thereās no lack of cool jumpscares and monster designs here, but The Mist never stops being about family, a family that ends up having to face making a decision that youāll never forget.

The Fly (David Cronenberg, 1986)
The Fly references in more popular media are so prevalent that younger audiences might attribute the accidental mix between a person and an insect to a surprisingly popular trope, not a specific film. Still, David Cronenbergās The Fly is much more than the imagining of one of humanityās (apparent) greatest fears.
Though we tend to remember the scene of the accident and the very gory climax of the film, the entire deterioration of Jeff Goldblumās character is more than worthy of everyoneās time.

Spring (Justin Benson, Aaron Moorhead, 2015)
Spring ups the Sci-Fi Horror ante by inviting Romance in. Yes, even though it features spooky monsters and scientific concepts are thrown around, those take the backseat to a surprisingly great love story between a regular guy and a mysterious Italian woman. Spring wouldāve been an interesting experiment even if it had failed in the daunting task it set out to achieve, but it doesnāt.
Itās heartbreaking that not many people know about this one, and thereās only one way to fix that.

28 Days Later (Danny Boyle, 2003)
While itās only natural to think of George A. Romeroās movies or Resident Evil when you think about Zombies, itās hard to deny how much 28 Days Later revitalized the genre.
Running infected were some of the most divisive movie monsters when we first saw them, but now we can all admit theyāre much scarier than the classic zombie type. Also, 28 Days Later doesnāt just rest upon this update, as it weaves a personal and at some points even heartwarming tale of survival in an outbreak-ravaged England that youāll never forget.

Aniara (Hugo Lilja, Pella KƄgerman, 2019)
Aniara invites viewers to see what an interstellar cruise ship trip might look like, too bad it picks the worst possible voyage to promote this cool new type of travel. Aniara doesnāt feature the space equivalent of an Iceberg crash that quickly leads to the sinking of a ship. Instead, it masterfully shows the slow descent into madness of a shipās crew that accidentally strayed off course and has to come to terms with the possibility of never reaching the destination.
While Aniara doesnāt feature jumpscares, itās hard to ignore all the existential dread it fills viewers with by constantly giving them new hope and squashing it in front of their eyes.

Cube (Vincenzo Natali, 2000)
As far as low-budget sci-fi horror goes, I doubt you can do better than Cube ā In fact, some of its darkest aspects are so well-conceived that youāll have a hard time noticing it was even low-budget.
Cube invites viewers to experience a reality where a bunch of people are seemingly put at random into a megastructure composed of cubes that lead into other cubes, some of which feature deadly traps. The movie offers no answers, which helps the incredible violence of Cube feel extremely alien ā or something late-stage capitalist humans would totally come up with.
Alien (Ridley Scott, 1979)
Ever since the release of Aliens, fans have been arguing over which is the best between the two original Alien films. Aliens fits more neatly in the sci-fi action category, and, as for the main reason why itās not featured on this list, well, I just donāt think it measures up to the original.
The original Alien from 1979 set an incredibly high bar for Sci-Fi horror by introducing us to a story equal parts Sci-Fi and Gothic Horror. Unlike Aliens, Alien revels in its buildup, and the moments we spend trying to understand whatās happening and watching the Xenomorph grow are as enthralling as the moments we spend being afraid once this perfect killing machine reaches maturity.

Predator (John McTiernan,1987)
If you like the action of Die Hard, Terminator, or even Commando, Predator has that for you, but what sets it apart is a brilliant genre subversion. Predator follows a group of soldiers led by Arnold Schwarzenegger, who are naturally the biggest and baddest dudes in the world ā but not in the Universe.
After a mission in which Arnieās squad kills an entire battalion like it was a video game tutorial, they start dropping one by one in a gruesome fashion. Out of nowhere, what you thought would be another celebration of testosterone, turns into a slasher where the hopeless victims are all badasses youād think each couldāve carried their own horror movies. On top of all the beautifully well-realized Sci-Fi and Horror crossover, Predator cements Arnie as the greatest action hero of them all by showing how the man isnāt afraid of getting slapped around by something bigger and stronger that forces him to use his wits to come out on top.

The Thing (John Carpenter, 1982)
What makes The Thing special isnāt the evil shapeshifting alien that hunts down the members of a likable crew one by one ā though it features the best practical effects ever seen in cinema history. Itās the sense of dread you cannot shake by having to constantly wonder whoās the monster and whoās just an equally dangerous human on the verge of losing it.
John Carpenterās loose remake of Howard Hawksās The Thing From Another World was a critical and commercial flop upon release, with Roger Ebert seeing it as little more than āĀ a gross-out movie in which teenagers can dare one another to watch the screenā. Still, I believe thereās no better possible laurel for a sci-fi work than coming out ahead of its time, and The Thing was quick to get a cultural reappraisal that propelled it into the podium of sci-fi horror, which it hasnāt left since.