I can see why the couple of reviewers out of a thousand didn't like the movie; the movie's somewhat force-fed commentary on humans, consumerism, and how we're killing the environment.
Besides that it's was truly excellent.
You can tell they spent a lot of time putting a lot of detail into the film. I just love the way Wall-e moves around sometimes. That alone makes me smile. I must say that Pixar is really awesome for making a film without any dialogue for nearly the first 40 minutes. This truly speaks to the genius work of sound designer Ben Burtt.
A 97% on Rotten Tomatoes!!!