Lord of the Rings.
Although, if you didn't know, you can pretty much skip this.
One year for Christmas, Kerry got me the LOTR set on DVD. Not every year, but most, we pick a cold, dark Saturday during the winter, farm out the boys, and have a LOTR marathon. And let me tell you, no matter how much you like them (and we do), watching all three, back to back, is an endurance event. 12+ hours of screen time.
And yes, I said we farm the boys out. As yet, we have not let the boys watch them. While there is much to admire in the stories, they are definitely dark. As the years have gone by, the boys have heard us discussing the movies and asked me when they'd be old enough to watch them, and I have always said...
When you read the books, you can watch the movies.
Guess who is going to be watching with us this year?