Just like "worth the price of admission," "must-see" is an oft-overused descriptor for critics desperate for shorthand to proclaim a film's value. But James Cameron's long-gestating project Avatar left me speechless, searching for words to describe the impossible-seeming vision unfolding on the screen and trying to pry my jaw off the popcorn-and-candy-covered floor of the theater. Are "unmissable" and "essential" really any less lazy—or less true? Not seeing Avatar will not only leave people out of the cultural conversation sure to revolve around water coolers — not to mention around its incredible special effects — but they'll also miss a landmark in moviemaking.

Set in 2154, Avatar begins with the now-familiar premise that humanity has torn through its natural resources and now must look elsewhere for its necessities. The far-off planet of Pandora may provide a solution: beneath its lush jungles and thriving plains lies stores of Unobtainium, a highly valuable substance that could be used as energy on Earth. Since Pandora's air is poisonous to humans, special bodies called avatars have been created by combining the DNA of humans and Pandora's population, called the Na'vi. Human operators can control these bodies remotely from the safety of the human base.

After the death of his brother, former marine Jake Sully (Sam Worthington, Terminator Salvation) is asked to take his place in the avatar program. Since Jake is in a wheelchair, the opportunity to move unencumbered is even more attractive than exploring an alien world. But once Jake arrives on Pandora, he is swept into the culture of the Na'vi, even as he is torn between the exploratory mission of Dr. Grace Augustine (Sigourney Weaver, Aliens) and the destructive one of Col. Miles Quaritch (Stephen Lang, The Men Who Stare at Goats). He finds kinship with the Na'vi, particularly with female warrior Neytiri (Zoë Saldana, Star Trek), and he soon finds he must decide where he belongs.

Avatar is a work of striking originality; not in its pedestrian, Pocahontas-like plot, but in its execution. In fact, the simplicity and familiarity of its storyline allow the audience to concentrate solely on the remarkable visuals. It seamlessly blends live action with CG animation, using WETA's efforts and performance capture to create an entirely believable world.

The on-screen technology and biology are breathtaking, particularly the plant and animal life on Pandora. Trying to describe the well-imagined and well-executed creations seems impossible, and it would take away from the wonder the audience experiences as they see the planet and its inhabitants through Jake's eyes. What he sees on Pandora is entirely new to him, and it's a similar feeling for us. What we're witnessing has never been done before, at least not this well.

The final fight scene in the Pandora jungle is so epic that it makes Return of the Jedi's Battle of Endor look like it was fought by, well, teddy bears. This is a big, bold film that could fall into the George Lucas school of filmmaking where technology trumps story, characterization, and dialogue—except that with Avatar it actually works.

Acting may seem like an afterthought in Avatar's special-effects-laden world, but Cameron's cast ably inhabits their characters and environments. Worthington works a brutish charm that is evident whether he is human or appears in Na'vi skin, and Saldana exhibits both grace and ferociousness as Neytiri. Lang is a mere step away from caricature with his snarling Col. Quaritch, but he's an effective villain within Cameron's black-and-white world. Weaver shows the typical strength we've come to expect from the director's female characters, and Michelle Rodriguez's role as a pilot is a nice addition to his stable, as well.

Cameron's Avatar is so much fun that it almost doesn't matter that the dialogue was Lucas-level cheesy. If you are hoping for witty repartee, go to a Noel Coward play. But for filmgoers that want to be inspired by the future of action cinema, this is just the ticket. Avatar isn't quite as big of a game changer as its filmmakers might like you to believe. But it's not far from it.