I've read the original novella, "I Am Legend", seen the Vincent Price version, and the Will Smith version as well as the Omega Man. They're all a bit toned down from the novella. The original was very pretty depressing and bleak and also inspired modern zombies. The end of the novella is one of the reasons it's considered classic of vampire fiction. The later movies changed it make the end a bit more "happy" I guess.
There are the older movies that have the greatest rewatch value, at least for me:
~Gone With The Wind (1939)
~The Quiet Man (1952)
~Ten Commandments (1956)
~Gigi (1958)
~The Birds (1963)
~Sound of Music (1965)
~Yours Mine and Ours (1968)
~The Shining (1980)
~Victor/Victoria (1982)
And the original Twilight Zone series (1959) has massive rewatch value. I can watch it on marathon over and over and never get tired of it, lol.
OH prepare for a long list, I love watching movies!
My faves (links to trailers) -cracks knuckles-:
Serial Mom
Jacob's Ladder
Eraserhead
As Good As It Gets
One Flew Over The Cuckoo's Nest
A Nightmare on Elm Street 1 and 2
Perfect Blue
Sleepaway Camp
Tombstone (partially because my uncle played a random background dude in it.)
My Neighbor Totoro
Princess Mononoke
Porky's
Full Metal Jacket
Little Shop of Horrors
Nausicaä of the Valley of the Wind
Beetlejuice
Weird Science
Revenge of the Nerds
Edward Scissorhands
Blazing Saddles
Risky Business
Cannibal Holocaust (really messed up movie, only watch it if you like critical commentary films, and can handle upsetting visuals.)
Dune
*Batteries Not Included
The Goonies
Titanic
Grave of the Fireflies
Clue
Rocky Horror Picture Show
Airplane 1 and 2.
Naked Gun 1, 2½ and 33⅓.
Grease
Conan The Barbarian
Most of the Police Academy movies.
Top Secret
Misery
Cube
Alien
Species
Footloose
The Dark Crystal
The Holy Mountain
M*A*S*H
A Clockwork Orange
Jaws
Watership Down
Phantom Of The Paradise
Dead Poet Society
Akira
Romancing the Stone
Ghostbusters
The Thing
The Bear/L'Ours
Return to Oz
Starship Troopers
Back to the Future 1,2 and 3.
The Fifth Element
There are more I'm sure, but these are the ones I remember off the top of my head. I would describe what I like about them all, but then I would be here all night.
I love Jim Jarmusch movies and "Night on earth" is my favourite because that´s the first one I saw by JJ but they
are all good. Coffee & Cigarettes, Down by law etc
I saw Night on earth when I was 16 in 1991 and it changed my movie life because I finally found a movie
genre that I love.
The Wanderers is the movie I watched the most beside Star Wars IV-VI
Beside that I´m really interested in movies from the 20s - 50s, I love the connection between rock´n´roll
and movies in movies like "the girl can´t help it"
When I was 14 I was a big James Dean fan, Rebel without a cause is his best one.
I love movies that surprise the viewer like old boy but that´s not really old (2003)
Oh man, where to start...
I mostly watch horror, so there I have to recommend
-Freaks (1932)
-Whatever Happened to Baby Jane (1962)
-Man Bites Dog (1992) this is one of the most disturbing films I've ever seen, watch with caution
-Henry: Portrait of a Serial Killer (1986)
-Ginger Snaps (2001)
-Dead Alive (1993)
-Haxan (1922)
-Anything made by Dario Argentines, and the 2019 Suspiria remakes very good as well
I'm sure as soon as I hit post I'll remember 20 more, lol
The Court Jester (1955) — Danny Kaye, Angela Lansbury, and Basil Rathbone.
It’s Danny Kaye. Need I say more? It’s hysterical
Operation Petticoat (1959) — Cary Grant, Tony Curtis.
One of the most hilarious naval films ever made
I’m so happy @DavidPerry mentioned Arsenic and Old Lace! I feel like it gets forgotten more often than not!
God, to think something from the 90's is old now. -sweats- I'm showing my age.
Anyway, for movies I've enjoyed that came out before I was born and that haven't been mentioned yet:
A Boy and His Dog (1975): weird post-apocalyptic story with some neat twists. And the dog talks~
the Man with No Name Trilogy (1964–1966): you know, A Fistful of Dollars, For a Few Dollars More, and The Good The Bad and The Ugly. Classics.
Roman Holiday (1953): another classic. All around charming. I enjoyed it more than I thought I would!
Fiddler on the Roof (1971): one of my favorite musicals and one of the best movie adaptations of a musical imo.
The Bad News Bears (1976): I'm a sucker for kid fights. Also enjoyed the comedy, like the kids are brats but not in the modern annoying way.
Road House (1989): heck of a good time, it's got silly moments and serious moments, but I was invested the whole while.
Glory (1989): one of my most favorite movies, if not the favorite. Love that period of history and I always get a swell of emotion for the characters.
Maurice (1987): another of my most favorite movies. Based on the book by E.M. Forster. Don't see many gay films from that time.
I may come up with more later, but these are the ones off the top of my head!