This one was an oldie even when I was growing up in the 1970s and 80s, but I found it terrifying - yet fascinating - nonetheless: The 1938 version of "The Adventures of Tom Sawyer", starring Tommy Kelly.
I found the movie entertaining, yet was terrifed of Victor Jory's "Injun Joe" character - from his throwing of the tomahawk during Tom's testimony in court, to his discovery of a lost Tom and Becky in the cave. I had nightmares of the scene Tom turning around to see Injun Joe standing there, watching them and grinning. Many a sleepless night was due to that one scene - yet I watched it every time they showed a matinee at our local theater or when it aired on TV.
I must have been somewhat masochistic when it came to fear, as I did the same thing with horror comic books.
Love the site, love "digging up" chilling memories.
Dustin in Minnesota