Since there don't seem to be many fans of the genre on here (1992?), I'll tackle the Horror films:
* I'm omitting "The Exorcist", "Jaws" and "Alien" as they are universally revered as royalty in the genre.
* I'm also omitting the classic horror icon monster movies like Frankenstein, Dracula, Wolfman, Mummy, Invisible Man and the Creature from the Black Lagoon.
* The "Friday the 13th", "Halloween" and "Nightmare on Elm Street" franchises brought us iconic horror villains but none of the individual films make my personal Top 10.
* I consider "Silence of the Lambs", "Se7en" and "Psycho" as dramatic "thrillers" rather than true horror films.
1. "The Texas Chainsaw Massacre" (1974) - Widely considered as the goriest film of all time, there is actually very little blood shown in the entire movie. When Leatherface slams the metal butcher's door closed, your imagination is all the gore you'll ever need as to what happens next. Director Tobe Hooper would later go on to direct "Poltergeist" but this film is what got me started - and kept me - as a lifelong fan of the Horror genre.
2. "The Evil Dead" (1981) - Directed by Sam Raimi who was eventually tabbed to direct the first Marvel "Spiderman" movie, the film is based on a book by H.P. Lovecraft called "Necronomicon", also known as "Book of the Dead". Resurrected by the reading of ancient Sumerian text, demons slowly take over the souls of four (4) unfortunate guests in an isolated cabin in the woods. What could go wrong? The pencil scene still scars my memories to this day and the vine seen in the woods would get Raimi in quite a bit of trouble before the studio allowed it in the movie.
3. "Hellraiser" (1987) - Nobody is more demented than Clive Barker and he introduces us to Pinhead and the Cenobites. They are summoned by the opening of an ancient puzzle box with ties to hell and they only have one goal in my mind - torture the person that opened the box for eternity. The origins of Pinhead and the Cenobites are revealed later in a sequel and how they became what they are is even more horrifying.
4. "The Devil's Rejects" (2005) - Rob Zombie's follow-up to "House of a Thousand Corpses" might be the most underappreciated horror film ever made. The Firefly family terrorizes anyone and everyone without discrimination and their characters are very well developed. The cast is widely made up of "B" movie actors but it's so well written and disturbing that you'd swear they aren't really acting. No monsters...just people...and they are terrifying. This is a "must see" movie for those not familiar with it.
5. "The Thing" (1982) -John Carpenter, Kurt Russell, Wilford Brimley and a shape-shifting alien uncovered by Norwegian scientists drilling in the icepack...how can you go wrong??? The special effects at the time blew me away and the ever-morphing monster can be anyone, or anything, in the film. When Russell's character is testing the blood, I still darn near poop myself every time.
6. "Hereditary" (2018) - Sometimes, things passed down from generation to generation are not always welcomed with open arms. The writing and acting performances for a horror flick are insanely good. I can't say much without giving away the movie, but I will say that it has two (2) of the most memorable death scenes ever on film. For me, this is easily the best horror movie produced in the last 15 years.
7. "Sinister" (2012) - I'm biased on this film because I love Ethan Hawke's work, but this movie absolutely creeps the eff out of me and I was always surprised it didn't get more fanfare from moviegoers. In a sense, it's based on a series of "snuff" films that a writer stumbles upon. Seeking inspiration for another hit book, he starts researching the authenticity of the films and their origins. IMO, this is another "must see" movie even if you're not a big fan of the genre.
8. "Cloverfield" (2008) - This film nudges out "Blair Witch Project" as the best of all the found footage films for me. It's basically a love story at its core...with a pissed off, enormous creature having a very bad day on Earth. It's a young cast with relatively unknowns at the time like Lizzy Caplan and T.J. Miller and they don't disappoint. You have no idea what's attacking NYC until about 2/3 of the way into the movie and the wait is well worth it.
9. "28 Days Later" (2002) - Yes...the great Cillian Murphy's first big break was in a zombie movie. Even back then, you just knew the dude was destined for a bright acting future as he captivates the screen. Murphy's character awakes from a coma to find out a virus has wiped out humanity and created flesh-eating people infected with a "rage" virus intended only for lab animals. This is the first zombie movie that I recall where they are fast, mobile and athletic. This is what "World War Z" was intended to be.
10. "Minnesota vs. Michigan Football" (2003) The Gophers were 6-0, ranked #13 in the Coaches Poll and #17 in the AP Poll, and hosting the Michigan Wolverines. Behind a monstrous rushing attack, they led 28-7 going into the fourth quarter. Then Michigan outscored them 31-7 in the final quarter of play to complete a stunning 38-35 comeback victory. It was so horrifying...so diabolical...so demented...so terrifying, that I've never been able to watch it again. True horror.
Fun Fact: The 1980 Italian horror film, Cannibal Holocaust, was banned in over 140 countries worldwide. The movie is a Documentary-style film about students that travel to the Amazon to study the indigenous tribes of the area. The scenes were so graphic and realistic that the Director was charged with murder by the Italian Government and faced life in prison because all of the actors had been sequestered during the promotion and subsequent release of the film. It wasn't until the actors appeared in court proving they were still alive that the murder charges were eventually dropped. I watched the film 30 years ago and I would not recommend eating while enjoying the flick.