I second the old Disney movies, including the Haley Mills movies, especially That Darn Cat! 20,000 Leagues. Don't forget The Absent Minded Professor, the original Herbie the Love Bug. Also, Lassie movies and some old cowboy movies, like Shane. The Lone Ranger has 2 full-length movies, and all the old episodes are on Hulu for free. National Velvet. What about Little Women with Katherine Hepburn?
My girls have more adventurous tastes-- they like the original Gojira (Godzilla), Invasion of the Body Snatchers and The Thing From Outer Space. DD9 likes the old Sherlock Holmes movies (we laughed that one movie has Holmes saving the day from the Nazis!) Jaws... well, that might be too mature. My girls loved it. Close Encounters, though that's positively modern by comparison. Star Trek. Shinobi No Mono, a classic B&W ninja movie from Japan. Gilligan's Island-- we've now seen all 3 season's worth, confirming that I did indeed see every single episode in reruns growing up.
We've seen The Hunchback of Notre Dame with Lon Chaney (silent) as well as Gold Rush with Charlie Chaplin. The Lost World, another AC Doyle story made into a silent picture-- with amazing special effects (for the 1920's) and Spooooky-Funny dinosaurs. Our Gang/Little Rascals wasn't well received, though it was one of my favorites, as were Abbott and Costello episodes.
Though they have a lot of sexism and suggestions of recreational sex, the 60's Bond movies are fun.
Now they've seen enough old movies, they aren't turned off by B&W like they used to be.
I'm sure there are a million more out there!
"She is a mermaid, but approach her with caution. Her mind swims at a depth most would drown in."