I just finished reading the novella "The Brave Little Toaster" by Thomas M. Disch, and I actually like the movie much, much more! This isn't just nostalgia talking, since I read the books "The Last Unicorn" and "The Neverending Story" as an adult and thought they far outclassed their movie adaptations. (though I still love the movies!) :-)
I'm also not ashamed to admit that I prefered Steven Spielberg's "Jurassic Park" to Michael Crichton's "Jurassic Park."
I can think of several others, but how about you?