Labyrinth
The plot: The goblin king kidnaps Sarah's little brother and she has 13 hours to make it through the Labyrinth to the goblin king's castle in order to save him.The good: David Bowie! How can you go wrong when the goblin king is also providing 80's rock music? It's just generally a fun adventure?
The bad: It's like twenty years old now and kids are used to all the cool special effects despite how good the puppets are.
Conclusion: It's a fun adventure to show your kids.