The Return of the Rings has everything that these days make a film great: a good story, colorful characters, perfect casting, excellent acting, sweeping scenery, plenty of action and of course, ample special effects. However, I did not find the film to be completly worth all the expectation.
The action in the film is plentiful and much of it is very, very fast. It was difficult for me to focus and see what was happening through the speed. It has headache-inducing possibilities. The enemy is gruesome and they do gruesome things. Watch out for when they catapult heads of men into the White City. It's not for the squeamish. The huge oliphants are really neat and Legolas' fantastic feat of the film is to single-handedly take one down. But again, I wish the sweeping camera had slowed down so I could have appreciated it.Warning: plot spoilers following.The characters are, of course what really makes this trilogy work so well both in print and on film. The friendshp between Frodo and Sam is tested as Gollum pits them against each other. Though Frodo hurts Sam deeply with his words, Sam is undaunted in his devotion. Isn't it the same in real life, that you often hurt those who you love the most? Gollum, often cute and funny in The Two Towers, is truly evil and disgusting in this film. How his insatiable need for the ring is actually essential to the happy ending is part of what makes the story great.
I wish there had been more of this kind of attention to the story of all the humans. In short, I found very little returning of the King. True, he shows his courage in his prowess in battle and by gathering ghosts to fight (characters no scarier than the skeletal pirates in Pirates of the Caribean). But his speeches to his troops were uninspiring, and his coronation short. His reunion with Arwen was certainly the romantic highlight of the movie, and I thought, beautiful. For the length of the film, I actually thought Arwen had a good, strong part. She makes her decision, stands up to her father and makes sure the broken "magical" sword is reforged and given to Aragorn. Eowyn too, is strong as she defies all the men in her life and fights in the big battle. She also believes in Merry, and together they kill the most evil of the black riders and his even blacker dragon. I only wish she'd been given a little more screen time to fall in love with Faramir, not just a smile in the shadow of Aragorn and Arwen. And the conversation she has with the dying Theoden, a wimp of a king who is finally strong, is full of cliches. One human who gets ample time is Denethor, the Dad of Faramir and Boromir (remember him, way back in the Fellowship?). He is quite evil and slimy and yet we are never told that the real reason is his alliance with Sauron, the REAL bad guy. There is a sad scene when he, engulfed in flames, jumps off a cliff. It could bring unpleasant recollections for some.
It was nice to see characters grow up., Merry and Pippin especially. Though standard fools at the beginning of the trilogy, they prove themselves to be as brave, intellegent and nobel as the best of men, wizards and elves. In fact, there is a very nice scene where all the hobbits are honored. It echos Galadriels words in the Fellowship "even the smallest of persons can change the course of history". (I am surprised she wasn't there to say them. She, sadly, is missing until the very, very end).
So I suppose that is what makes the film great, the time honored virtues of good vs evil, the triumph of the underdog, cooperation between races, and the large effect of the smallest of deeds. For that, it is worth seeing as a family. As it is so long, fast and violent it may be worth taking the time to screen it first, and/or watch it next fall when it comes out on video.
If you and your family haven't read the books, I highly recommend them, especially after you've seen the film. The books are very long and having a visual picture of characters and setting really helps. It's worth reading at least some passages to your kids, they'll like it. Few films can compare with great books. With all our technology, I'm glad we still enjoy both.