Highly entertaining, but also... enlightening
A tornado rips through Dorothy's home in Kansas and transports her to the land of Oz where she meets a scarecrow in need of a brain, a tin man in need of a heart and a lion in need of courage. So they venture to the Emerald City in search of the eponymous wizard. 
"The Wizard of Oz" (1939) is eminently entertaining for both kids and adults. The message is great to boot. Yes, it's about developing your head, heart, and courage to find your way "home," but its most potent moral is about pulling back the curtain on political authorities and religion to expose the feeble phony pulling the levers.
Which isn't to say that all such authorities are phonies, of course, just that we need to be ever conscious of the fakes trying to manipulate us by pulling our strings.
The creators were smart to actually make the wicked witch of the west, her castle and flying monkeys creepy and horrific (in a comic booky way). 
The film runs 1 hour, 42 minutes.
GRADE: A+