Not to say that the movies are themselves gratuitous ... well, OK, I take that back. They mostly are, in different ways. None of them are Brand Shiny New; indeed, Shaun of the Dead came out in 2004.
Overall rating for Shaun of the Dead: 99 minutes of my life that I will never get back.
( Igor )
Overall rating for Igor: Fun entertainment in the style of The Nightmare before Christmas, even though it fails to reach Nightmare's level.
( Avatar )
Overall rating for Avatar: Typical action-movie-level entertainment as long as you're not expecting Robert Ludlum depths of plot. Shiny, shiny pixels really showcase what's possible with current CGI technology.
 Note that I do not include Pixar in this category. Pixar does good work; Disney largely just bought the right to put their own name on top of the credits for Pixar productions, and I'll give them credit for having the sense to mostly keep their hands out of Pixar's production process.
 Bonus points for back-of-the-envelope estimation of probable terminal velocity of the walker suit and probable Gs of deceleration on impact. Keep in mind that since the walker didn't visibly either embed its legs into the ground at all on impact, or bounce, said ground can reasonably be considered both rigid and inelastic.