The Wizard of Oz (1939)

There are tons of reviews and information on this movie-musical, which has been going strong for 70 years, so I'll spare a re-hash of the plot line, actors, etc... However, it was based on L. Frank Baum's 1900 novel The Wonderful World of Oz illustrating that Hollywood has been ripping off movie ideas for a long time.

What I like about this film is that it has science fiction, fantasy, and horror movie undertones with a strong female lead and a positive message. Very ahead of its time for cinema and probably a reason it has held up so well. On the negative side, I think it was the origin of my girlfriend's, and probably many others, pithikosophobia (fear of monkeys). While I was never much of a fan as a kid it has turned out to be one of my favorite movies over the years. Very easy to re-watch and compliments the fall thru winter months nicely.

The Pacific Science Center in Seattle even has 'Dark Side of the Rainbow' where Pink Floyd's Dark Side of the Moon is played while you watch The Wizard of Oz.

The fact that this can be watched without the original soundtrack is a testament to how truly imaginative, trippy, and intricate the sound stages and fantastical imagery are even after all these years. And when it comes to witches the Wicked Witch of the West is the pinnacle.